1. Afferent nerve fibres sensitive to changes in the renal chemical environment have been found i... more 1. Afferent nerve fibres sensitive to changes in the renal chemical environment have been found in the rat. To verify the existence of these fibres in the rabbit and their response pattern, afferent renal nerve activity was recorded during pelvic perfusions with NaCl solutions at different concentrations. 2. The experiments were carried out in 13 anaesthetized rabbits. Arterial pressure from a femoral catheter and afferent renal nerve activity from the distal stump of a cut renal nerve bundle were recorded. Three catheters were inserted into the renal pelvis to measure pelvic pressure, to allow pelvic perfusions at constant rates and to drain pelvic fluids. 3. After a control period, the pelvis was perfused with physiological saline (0.14 mol/l for 2 min), followed by one of a series of solutions containing increasing concentrations of NaCl (0.5, 0.75, 1.0 and 1.5 mol/l for 2 min). Pelvic perfusion was performed both at a low (0.2 ml/min) and a high (0.8 ml/min) flow rate for each s...
Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association, Jan 28, 2014
Oral anticoagulation therapy (OAT) is the choice treatment for thromboembolism prevention in atri... more Oral anticoagulation therapy (OAT) is the choice treatment for thromboembolism prevention in atrial fibrillation (AF), although data about OAT use in haemodialysis (HD) patients with AF are contradictory. The effect of OAT on the risk of mortality, stroke and bleeding was prospectively evaluated in a population of HD patients with AF. All the patients of 10 HD Italian centres alive on 31 October 2010 with documented AF episode(s) were recruited and followed-up for 2 years. OAT and antiplatelet intake, age, dialytic age, comorbidities and percentage time in the target international normalized ratio (INR) range (target therapeutic range; TTR) were considered as predictors of hazard of death, thromboembolic and bleeding events. At recruitment, 134 patients out of 290 were taking OAT. During the follow-up, 115 patients died (4 strokes, 3 haemorrhagic and 1 thromboembolic). Antiplatelet therapy, but not OAT, was associated with increased mortality (HR 1.71, CI 1.10-2.64, P = 0.02). The e...
Objective: The use of combination antiretroviral therapy has decreased AIDS–related mortality. It... more Objective: The use of combination antiretroviral therapy has decreased AIDS–related mortality. It has been observed that treated AIDS patients now have a greater cardiovascular mortality and early organ damage even without hypertension. Goals of our study have been to determine whether 1) in normotensive AIDS patients with or without renal damage there are functional (arterial stiffening) and structural (carotid wall thickening) large artery alterations and whether 2) this leads to alterations in an important predictor of cardiovascular events, i.e. central blood pressure (BP). Design and Methods: We studied 40 treated, normotensive, normocholesterolemic, euglycemic AIDS patients, with (n = 20, age 52.0 ± 2.6 years; BP 131/77 ± 4/2 mmHg, means ± SE) or without (n = 20, age 44.0 ± 2.0 years; BP 130/76 ± 2/1 mmHg) renal damage, and 20 healthy controls (C, age 52.0 ± 1.0 years; BP 124/77 ± 2/1 mmHg). Renal damage was defined by microalbuminuria and/or glomerular filtration rate < 60 ml/min. Arterial distensibility was measured by aorto-femoral Pulse Wave Velocity (PWV), central systolic BP by tonometry (Sphygmocor) and carotid artery intima-media thickness (IMT) by semi-automatic echotracking (WTS). Results: Compared to C AIDS patients without renal damage showed similar values of carotid IMT (543 ± 26 vs 554 ± 24 μm), PWV (11.0 ± 0.5 vs 10.3 ± 0.4 m/sec) and central BP (117 ± 2/77 ± 1 vs 115 ± 2/70 ± 3 mmHg). In contrast, all values were greater in AIDS patients with renal damage (IMT: 608 ± 26 μm, PWV: 11.0 ± 0.5 and central BP130 ± 3/77 ± 2 mmHg), the difference being statistically significant (+ 13 mmHg, p < 0.05) for central systolic BP. In AIDS patients, PWV showed a not significant correlation with creatinine (r = 0.3) and filtration rate, both when measured by Cokroft-Gault and by MDRD (r = 0.35 and 0.31) formula, while automatically calculated IMT and systolic BP significantly correlated between each other (r = 0.4). Conclusion: In normotensive AIDS patients with no major cardiovascular risk factors there is no apparent alteration in arterial structure and function. This alteration is evident in AIDS patients with renal damage, leading to a greater central BP value that might account for their increased cardiovascular risk.
1. Experiments were done on anaesthetized cats to study the effect of electrical stimulation of a... more 1. Experiments were done on anaesthetized cats to study the effect of electrical stimulation of afferent renal nerves on the circulatory system and on the release of renin from the kidney. 2. Stimulation of afferent renal nerves over a wide range of parameters consistently elicited an increase in arterial pressure and heart rate. This response was still present in paralysed animals and was not accompanied by changes in respiration or in sympathetic autonomic activity usually associated with painful stimulation. Mesenteric and iliac vasoconstriction was observed concomitantly with the increase in arterial pressure. 3. Release of renin from the contralateral innervated kidney was not significantly changed by stimulation of afferent renal nerves. 4. The existence of renal vascular mechanoreceptors was investigated by altering renal circulation. Stenosis of the renal artery or a marked reduction in renal perfusion pressure elicited an increase in arterial pressure while stenosis of the ...
Giornale italiano di nefrologia : organo ufficiale della Società italiana di nefrologia
The implementation of European Commission directives has radically modified occupational risk man... more The implementation of European Commission directives has radically modified occupational risk management. In fact, widespread and continuous education addressed to exposed workers is seen by the legislator as one of the most effective means to avoid occupational diseases. The recent establishment of Continuing Medical Education (CME) has helped the system grant CME credits to participants in occupational courses organized by health-care providers. Moreover, the constant development of new health technologies coupled with the high productivity of the legislator confer a short lifetime on the acquired knowledge. Biological risks, biomechanical overload of the lumbar spine, and stress are among the classical risks requiring attention, discussion, and regular updating. Not only health-care workers but also safety technicians, occupational physicians, managers and union representatives should receive scheduled refresher training. Modern technologies such as distance learning, interactive...
Urinary exosomes (UE) are nanovesicles released by every epithelial cell facing the urinary space... more Urinary exosomes (UE) are nanovesicles released by every epithelial cell facing the urinary space and they are considered a promising source of molecular markers for renal dysfunction and structural injury. Exosomal proteomics has emerged as a powerful tool for understanding the molecular composition of exosomes and has potential to accelerate biomarker discovery. We employed this strategy in the study of diabetic nephropathy (DN) and the consequent end stage renal disease, which represent the dramatic evolution of diabetes, often leading the patients to dialysis or kidney transplantation. The identification of DN biomarkers is likely to help monitoring the disease onset and progression. A label free LC-MS/MS approach was applied to investigate the alteration of the proteome of urinary exosomes isolated from the Zucker diabetic fatty rats (ZDF), as a model of type 2 DN. We collected 24 hour urine samples from 7 ZDF and from 7 control rats at different ages (6, 12 and 20 weeks old) to monitor the development of DN. Exosomes were isolated by ultracentrifugation and their purity assessed by immunoblotting for known exosomal markers. Exosomal proteins from urine samples of 20 week old rats were pooled and analyzed by nLC-ESI-UHR-QToF-MS/MS after pre-filtration and tryptic digestion, leading to the identification and label free quantification of 286 proteins. Subcellular localization and molecular functions were assigned to each protein by UniprotKB, showing that the majority of identified proteins were membrane-associated or cytoplasmic and involved in transport, signalling and cellular adhesion, typical functions of exosomal proteins. We further validated label free mass spectrometry results by immunoblotting, as exemplified by: Xaa-Pro dipeptidase, Major Urinary Protein 1 and Neprilysin, which resulted increased, decreased and not different, respectively, in exosomes isolated from diabetic urine samples compared to controls, by both techniques. In conclusion we show the potential of exosome proteomics for DN biomarker discovery.
It has been shown that angiotensin II (Ang II) induces the expression of calponin, a 34 kD actin-... more It has been shown that angiotensin II (Ang II) induces the expression of calponin, a 34 kD actin-binding protein, in vascular smooth muscle cells in vitro. The aim of this study was to investigate whether Ang II can modulate calponin gene expression in rat aorta in vivo. Aortic calponin gene expression was studied after chronic exogenous Ang II administration and in Goldblatt hypertension. To investigate the effect of Ang II administration, Sprague Dawley rats were treated for 6 days with a continuous infusion of Ang II (200 ng/kg per min) or saline by osmotic minipumps. The effect of endogenous Ang II on aortic calponin mRNA expression was studied in Goldblatt hypertensive rats with (2K1C model), or without (1K1C model) activation of the renin-angiotensin system. In particular, calponin gene expression in 2K1C rats was studied both at 1 week (2K1C-HR, high renin) and 4 weeks after the onset of hypertension, when plasma renin activity (PRA) was returned to normal values (2K1C-NR, normal renin). Systolic blood pressure (SBP) was measured twice a week. At the end of the experimental period, PRA was measured by radioimmunoassay, and aortic calponin gene expression was measured by Northern hybridization. SBP was significantly higher (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01), whereas PRA was suppressed (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01), in Ang II versus saline-treated rats. Northern hybridization showed that the aortic calponin gene expression significantly increased (2.5-fold) in Ang II-treated rats (P = 0.01). In Goldblatt hypertensive rats, SBP was significantly higher in 2K1C-HR (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01), 2K1C-NR (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and 1K1C (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) rats compared with the corresponding sham-treated rats. Activation of the renin-angiotensin system was present only in 2K1C-HR rats (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01), and Northern analysis showed that aortic calponin mRNA expression was significantly increased (2.2-fold) in this group of rats only (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01). Our data demonstrate that both exogenous and endogenous Ang II increase calponin gene expression in aortic smooth muscle cells, independently of the hemodynamic effect of Ang II.
Clinical and Experimental Pharmacology and Physiology, 2007
1. Angiotensin (Ang) II plays a major role in vascular remodelling. Matrix metalloproteinases (MM... more 1. Angiotensin (Ang) II plays a major role in vascular remodelling. Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are involved in the tissue remodelling processes. The aim of the present study was to investigate whether AngII modulates TIMP-2 expression in rat aortic smooth muscle cells in vivo. 2. Angiotensin II (200 ng/kg per min, s.c.) or AngII + losartan (10 mg/kg per day, s.c.) or normal saline was administered continuously by osmotic minipumps to Sprague-Dawley rats for 1 week. In addition, the effect of endogenous AngII on TIMP-2 expression was evaluated in renovascular hypertensive rats (two kidney, one clip (2K1C) and one kidney, one clip (1K1C) models). Control rats (sham 2K1C and sham 1K1C rats) underwent sham-clipping of the left renal artery. At the end of the treatment, plasma renin activity was measured by radioimmunoassay, aortic TIMP-2 mRNA expression was evaluated by real-time polymerase chain reaction and/or northern blotting and protein expression was evaluated by immunohistochemistry. Systolic blood pressure (SBP) was measured twice a week by the tail-cuff method. 3. Exogenous AngII administration produced the expected increase in SBP (P = 0.02) compared with the control saline-treated group. The increase in SBP was abolished in AngII + losartan-treated rats. Administration of AngII caused a significant increase in TIMP-2 expression (P = 0.01) in rat aortic smooth muscle cells that was abolished in AngII + losartan-treated rats. In renovascular hypertensive rats, SBP was higher (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001) in 2K1C and 1K1C rats compared with the corresponding sham-operated rats. Plasma renin activity was higher (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) in 2K1C rats compared with the other groups. The expression of TIMP-2 was significantly (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) increased only in 2K1C rats. 4. Our in vivo data demonstrate that exogenous and endogenous AngII increases TIMP-2 expression in rat aortic smooth muscle cells. This effect is not dependent on the AngII-induced increase in blood pressure and is mediated by angiotensin AT1 receptors.
Electrical stimulation of afferent renal nerves elicits an increase in arterial pressure and hear... more Electrical stimulation of afferent renal nerves elicits an increase in arterial pressure and heart rate. The hypertensive response is presumably due to the widespread activation of the sympathetic nervous system leading to peripheral vasoconstriction. Interestingly, the kidney does not appear involved in this reflex excitatory response to afferent renal nerve stimulation since changes in vascular conductances and excretory functions are equal in both the innervated and denervated kidney, and secondary to changes in renal perfusion pressure. In addition, no changes in renin release from either kidneys are observed during afferent renal nerve stimulation. It is likely that the electrical stimulation of afferent renal nerves activates other reflexes exerting an inhibitory influence on efferent renal nerve activity. Indeed, neural renorenal reflexes which tonically inhibit renal functions have clearly been demonstrated. Furthermore, preferential inhibition of efferent renal nerve activity by cardiopulmonary and sinoaortic receptors has recently been shown during activation of other visceral afferents.
Diabetic nephropathy is the main cause of end-stage renal disease. N-acetyl-seryl-aspartyl-lysyl-... more Diabetic nephropathy is the main cause of end-stage renal disease. N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP), a physiological tetrapeptide hydrolyzed by the angiotensin-converting enzyme (ACE), has antifibrotic effects in the cardiovascular system and in the kidney in experimental models of hypertension, heart failure and renal disease. The aim of the study was to evaluate the effect of Ac-SDKP in diabetic nephropathy and the potential additive effect of Ac-SDKP, when compared to ACE inhibitors alone, on the development of renal fibrosis. Diabetes was induced in 28 Sprague-Dawley rats by a single intraperitoneal injection of streptozotocin. Control rats (n = 10) received only buffer solution. An ACE inhibitor (ramipril, 3 mg/kg/day) was administered to 11 diabetic rats. After 2 months, Ac-SDKP (1 mg/kg/day) was administered by osmotic minipumps for 8 weeks to 7 diabetic rats and to 6 diabetic rats treated with ramipril. Osmotic minipumps delivered saline solution in the corresponding sham-treated rats (diabetic rats, n = 10, and ramipril-treated diabetic rats, n = 5). Diabetic rats showed a significant increase in blood glucose level, urinary albumin excretion and renal fibrosis, and a reduction of glomerular nephrin expression with respect to control rats. Ac-SDKP administration significantly reduced renal fibrosis in diabetic rats, without significantly reducing urinary albumin excretion. Ramipril treatment caused a significant decrease in albuminuria and renal fibrosis and restored glomerular nephrin expression. Administration of Ac-SDKP, in addition to ramipril, further reduced renal fibrosis with respect to ramipril alone, while it did not improve the antiproteinuric effect of ramipril. Ac-SDKP administration reduces renal fibrosis in diabetic nephropathy. Addition of Ac-SDKP to ACE inhibition therapy improves the reduction of renal fibrosis with respect to ACE inhibition alone, suggesting a beneficial effect of this pharmacological association in diabetic nephropathy.
Mechanoreceptors and chemoreceptors have been identified inside the kidney, but their functional ... more Mechanoreceptors and chemoreceptors have been identified inside the kidney, but their functional role is still largely unclear. The aim of this study was to investigate whether changes in urine output could modify the discharge rate of renal afferent fibers. Experiments were performed in anesthetized cats in which afferent renal nerve activity (ARNA) was recorded by standard electrophysiological techniques from a centrally cut renal nerve. Arterial pressure, renal blood flow velocity, urine flow rate, and renal pelvic pressure were also measured. Three diuretic maneuvers were tested in the same cat: intravenous administration of physiological saline (8 to 13 mL/min for 2 minutes), furosemide (1 mg/kg), and atrial natriuretic peptide (ANP, 1 microgram/kg). The three maneuvers increased urine flow rate and pelvic pressure, respectively, 137.0 +/- 20.6% and 136.8 +/- 21.1% (saline), 148.6 +/- 31.7% and 139.6 +/- 43.5% (furosemide), and 75.9 +/- 7.9% and 62.1 +/- 21.2% (ANP) at the time...
1. Afferent nerve fibres sensitive to changes in the renal chemical environment have been found i... more 1. Afferent nerve fibres sensitive to changes in the renal chemical environment have been found in the rat. To verify the existence of these fibres in the rabbit and their response pattern, afferent renal nerve activity was recorded during pelvic perfusions with NaCl solutions at different concentrations. 2. The experiments were carried out in 13 anaesthetized rabbits. Arterial pressure from a femoral catheter and afferent renal nerve activity from the distal stump of a cut renal nerve bundle were recorded. Three catheters were inserted into the renal pelvis to measure pelvic pressure, to allow pelvic perfusions at constant rates and to drain pelvic fluids. 3. After a control period, the pelvis was perfused with physiological saline (0.14 mol/l for 2 min), followed by one of a series of solutions containing increasing concentrations of NaCl (0.5, 0.75, 1.0 and 1.5 mol/l for 2 min). Pelvic perfusion was performed both at a low (0.2 ml/min) and a high (0.8 ml/min) flow rate for each s...
Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association, Jan 28, 2014
Oral anticoagulation therapy (OAT) is the choice treatment for thromboembolism prevention in atri... more Oral anticoagulation therapy (OAT) is the choice treatment for thromboembolism prevention in atrial fibrillation (AF), although data about OAT use in haemodialysis (HD) patients with AF are contradictory. The effect of OAT on the risk of mortality, stroke and bleeding was prospectively evaluated in a population of HD patients with AF. All the patients of 10 HD Italian centres alive on 31 October 2010 with documented AF episode(s) were recruited and followed-up for 2 years. OAT and antiplatelet intake, age, dialytic age, comorbidities and percentage time in the target international normalized ratio (INR) range (target therapeutic range; TTR) were considered as predictors of hazard of death, thromboembolic and bleeding events. At recruitment, 134 patients out of 290 were taking OAT. During the follow-up, 115 patients died (4 strokes, 3 haemorrhagic and 1 thromboembolic). Antiplatelet therapy, but not OAT, was associated with increased mortality (HR 1.71, CI 1.10-2.64, P = 0.02). The e...
Objective: The use of combination antiretroviral therapy has decreased AIDS–related mortality. It... more Objective: The use of combination antiretroviral therapy has decreased AIDS–related mortality. It has been observed that treated AIDS patients now have a greater cardiovascular mortality and early organ damage even without hypertension. Goals of our study have been to determine whether 1) in normotensive AIDS patients with or without renal damage there are functional (arterial stiffening) and structural (carotid wall thickening) large artery alterations and whether 2) this leads to alterations in an important predictor of cardiovascular events, i.e. central blood pressure (BP). Design and Methods: We studied 40 treated, normotensive, normocholesterolemic, euglycemic AIDS patients, with (n = 20, age 52.0 ± 2.6 years; BP 131/77 ± 4/2 mmHg, means ± SE) or without (n = 20, age 44.0 ± 2.0 years; BP 130/76 ± 2/1 mmHg) renal damage, and 20 healthy controls (C, age 52.0 ± 1.0 years; BP 124/77 ± 2/1 mmHg). Renal damage was defined by microalbuminuria and/or glomerular filtration rate < 60 ml/min. Arterial distensibility was measured by aorto-femoral Pulse Wave Velocity (PWV), central systolic BP by tonometry (Sphygmocor) and carotid artery intima-media thickness (IMT) by semi-automatic echotracking (WTS). Results: Compared to C AIDS patients without renal damage showed similar values of carotid IMT (543 ± 26 vs 554 ± 24 μm), PWV (11.0 ± 0.5 vs 10.3 ± 0.4 m/sec) and central BP (117 ± 2/77 ± 1 vs 115 ± 2/70 ± 3 mmHg). In contrast, all values were greater in AIDS patients with renal damage (IMT: 608 ± 26 μm, PWV: 11.0 ± 0.5 and central BP130 ± 3/77 ± 2 mmHg), the difference being statistically significant (+ 13 mmHg, p < 0.05) for central systolic BP. In AIDS patients, PWV showed a not significant correlation with creatinine (r = 0.3) and filtration rate, both when measured by Cokroft-Gault and by MDRD (r = 0.35 and 0.31) formula, while automatically calculated IMT and systolic BP significantly correlated between each other (r = 0.4). Conclusion: In normotensive AIDS patients with no major cardiovascular risk factors there is no apparent alteration in arterial structure and function. This alteration is evident in AIDS patients with renal damage, leading to a greater central BP value that might account for their increased cardiovascular risk.
1. Experiments were done on anaesthetized cats to study the effect of electrical stimulation of a... more 1. Experiments were done on anaesthetized cats to study the effect of electrical stimulation of afferent renal nerves on the circulatory system and on the release of renin from the kidney. 2. Stimulation of afferent renal nerves over a wide range of parameters consistently elicited an increase in arterial pressure and heart rate. This response was still present in paralysed animals and was not accompanied by changes in respiration or in sympathetic autonomic activity usually associated with painful stimulation. Mesenteric and iliac vasoconstriction was observed concomitantly with the increase in arterial pressure. 3. Release of renin from the contralateral innervated kidney was not significantly changed by stimulation of afferent renal nerves. 4. The existence of renal vascular mechanoreceptors was investigated by altering renal circulation. Stenosis of the renal artery or a marked reduction in renal perfusion pressure elicited an increase in arterial pressure while stenosis of the ...
Giornale italiano di nefrologia : organo ufficiale della Società italiana di nefrologia
The implementation of European Commission directives has radically modified occupational risk man... more The implementation of European Commission directives has radically modified occupational risk management. In fact, widespread and continuous education addressed to exposed workers is seen by the legislator as one of the most effective means to avoid occupational diseases. The recent establishment of Continuing Medical Education (CME) has helped the system grant CME credits to participants in occupational courses organized by health-care providers. Moreover, the constant development of new health technologies coupled with the high productivity of the legislator confer a short lifetime on the acquired knowledge. Biological risks, biomechanical overload of the lumbar spine, and stress are among the classical risks requiring attention, discussion, and regular updating. Not only health-care workers but also safety technicians, occupational physicians, managers and union representatives should receive scheduled refresher training. Modern technologies such as distance learning, interactive...
Urinary exosomes (UE) are nanovesicles released by every epithelial cell facing the urinary space... more Urinary exosomes (UE) are nanovesicles released by every epithelial cell facing the urinary space and they are considered a promising source of molecular markers for renal dysfunction and structural injury. Exosomal proteomics has emerged as a powerful tool for understanding the molecular composition of exosomes and has potential to accelerate biomarker discovery. We employed this strategy in the study of diabetic nephropathy (DN) and the consequent end stage renal disease, which represent the dramatic evolution of diabetes, often leading the patients to dialysis or kidney transplantation. The identification of DN biomarkers is likely to help monitoring the disease onset and progression. A label free LC-MS/MS approach was applied to investigate the alteration of the proteome of urinary exosomes isolated from the Zucker diabetic fatty rats (ZDF), as a model of type 2 DN. We collected 24 hour urine samples from 7 ZDF and from 7 control rats at different ages (6, 12 and 20 weeks old) to monitor the development of DN. Exosomes were isolated by ultracentrifugation and their purity assessed by immunoblotting for known exosomal markers. Exosomal proteins from urine samples of 20 week old rats were pooled and analyzed by nLC-ESI-UHR-QToF-MS/MS after pre-filtration and tryptic digestion, leading to the identification and label free quantification of 286 proteins. Subcellular localization and molecular functions were assigned to each protein by UniprotKB, showing that the majority of identified proteins were membrane-associated or cytoplasmic and involved in transport, signalling and cellular adhesion, typical functions of exosomal proteins. We further validated label free mass spectrometry results by immunoblotting, as exemplified by: Xaa-Pro dipeptidase, Major Urinary Protein 1 and Neprilysin, which resulted increased, decreased and not different, respectively, in exosomes isolated from diabetic urine samples compared to controls, by both techniques. In conclusion we show the potential of exosome proteomics for DN biomarker discovery.
It has been shown that angiotensin II (Ang II) induces the expression of calponin, a 34 kD actin-... more It has been shown that angiotensin II (Ang II) induces the expression of calponin, a 34 kD actin-binding protein, in vascular smooth muscle cells in vitro. The aim of this study was to investigate whether Ang II can modulate calponin gene expression in rat aorta in vivo. Aortic calponin gene expression was studied after chronic exogenous Ang II administration and in Goldblatt hypertension. To investigate the effect of Ang II administration, Sprague Dawley rats were treated for 6 days with a continuous infusion of Ang II (200 ng/kg per min) or saline by osmotic minipumps. The effect of endogenous Ang II on aortic calponin mRNA expression was studied in Goldblatt hypertensive rats with (2K1C model), or without (1K1C model) activation of the renin-angiotensin system. In particular, calponin gene expression in 2K1C rats was studied both at 1 week (2K1C-HR, high renin) and 4 weeks after the onset of hypertension, when plasma renin activity (PRA) was returned to normal values (2K1C-NR, normal renin). Systolic blood pressure (SBP) was measured twice a week. At the end of the experimental period, PRA was measured by radioimmunoassay, and aortic calponin gene expression was measured by Northern hybridization. SBP was significantly higher (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01), whereas PRA was suppressed (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01), in Ang II versus saline-treated rats. Northern hybridization showed that the aortic calponin gene expression significantly increased (2.5-fold) in Ang II-treated rats (P = 0.01). In Goldblatt hypertensive rats, SBP was significantly higher in 2K1C-HR (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01), 2K1C-NR (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and 1K1C (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) rats compared with the corresponding sham-treated rats. Activation of the renin-angiotensin system was present only in 2K1C-HR rats (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01), and Northern analysis showed that aortic calponin mRNA expression was significantly increased (2.2-fold) in this group of rats only (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01). Our data demonstrate that both exogenous and endogenous Ang II increase calponin gene expression in aortic smooth muscle cells, independently of the hemodynamic effect of Ang II.
Clinical and Experimental Pharmacology and Physiology, 2007
1. Angiotensin (Ang) II plays a major role in vascular remodelling. Matrix metalloproteinases (MM... more 1. Angiotensin (Ang) II plays a major role in vascular remodelling. Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are involved in the tissue remodelling processes. The aim of the present study was to investigate whether AngII modulates TIMP-2 expression in rat aortic smooth muscle cells in vivo. 2. Angiotensin II (200 ng/kg per min, s.c.) or AngII + losartan (10 mg/kg per day, s.c.) or normal saline was administered continuously by osmotic minipumps to Sprague-Dawley rats for 1 week. In addition, the effect of endogenous AngII on TIMP-2 expression was evaluated in renovascular hypertensive rats (two kidney, one clip (2K1C) and one kidney, one clip (1K1C) models). Control rats (sham 2K1C and sham 1K1C rats) underwent sham-clipping of the left renal artery. At the end of the treatment, plasma renin activity was measured by radioimmunoassay, aortic TIMP-2 mRNA expression was evaluated by real-time polymerase chain reaction and/or northern blotting and protein expression was evaluated by immunohistochemistry. Systolic blood pressure (SBP) was measured twice a week by the tail-cuff method. 3. Exogenous AngII administration produced the expected increase in SBP (P = 0.02) compared with the control saline-treated group. The increase in SBP was abolished in AngII + losartan-treated rats. Administration of AngII caused a significant increase in TIMP-2 expression (P = 0.01) in rat aortic smooth muscle cells that was abolished in AngII + losartan-treated rats. In renovascular hypertensive rats, SBP was higher (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001) in 2K1C and 1K1C rats compared with the corresponding sham-operated rats. Plasma renin activity was higher (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) in 2K1C rats compared with the other groups. The expression of TIMP-2 was significantly (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) increased only in 2K1C rats. 4. Our in vivo data demonstrate that exogenous and endogenous AngII increases TIMP-2 expression in rat aortic smooth muscle cells. This effect is not dependent on the AngII-induced increase in blood pressure and is mediated by angiotensin AT1 receptors.
Electrical stimulation of afferent renal nerves elicits an increase in arterial pressure and hear... more Electrical stimulation of afferent renal nerves elicits an increase in arterial pressure and heart rate. The hypertensive response is presumably due to the widespread activation of the sympathetic nervous system leading to peripheral vasoconstriction. Interestingly, the kidney does not appear involved in this reflex excitatory response to afferent renal nerve stimulation since changes in vascular conductances and excretory functions are equal in both the innervated and denervated kidney, and secondary to changes in renal perfusion pressure. In addition, no changes in renin release from either kidneys are observed during afferent renal nerve stimulation. It is likely that the electrical stimulation of afferent renal nerves activates other reflexes exerting an inhibitory influence on efferent renal nerve activity. Indeed, neural renorenal reflexes which tonically inhibit renal functions have clearly been demonstrated. Furthermore, preferential inhibition of efferent renal nerve activity by cardiopulmonary and sinoaortic receptors has recently been shown during activation of other visceral afferents.
Diabetic nephropathy is the main cause of end-stage renal disease. N-acetyl-seryl-aspartyl-lysyl-... more Diabetic nephropathy is the main cause of end-stage renal disease. N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP), a physiological tetrapeptide hydrolyzed by the angiotensin-converting enzyme (ACE), has antifibrotic effects in the cardiovascular system and in the kidney in experimental models of hypertension, heart failure and renal disease. The aim of the study was to evaluate the effect of Ac-SDKP in diabetic nephropathy and the potential additive effect of Ac-SDKP, when compared to ACE inhibitors alone, on the development of renal fibrosis. Diabetes was induced in 28 Sprague-Dawley rats by a single intraperitoneal injection of streptozotocin. Control rats (n = 10) received only buffer solution. An ACE inhibitor (ramipril, 3 mg/kg/day) was administered to 11 diabetic rats. After 2 months, Ac-SDKP (1 mg/kg/day) was administered by osmotic minipumps for 8 weeks to 7 diabetic rats and to 6 diabetic rats treated with ramipril. Osmotic minipumps delivered saline solution in the corresponding sham-treated rats (diabetic rats, n = 10, and ramipril-treated diabetic rats, n = 5). Diabetic rats showed a significant increase in blood glucose level, urinary albumin excretion and renal fibrosis, and a reduction of glomerular nephrin expression with respect to control rats. Ac-SDKP administration significantly reduced renal fibrosis in diabetic rats, without significantly reducing urinary albumin excretion. Ramipril treatment caused a significant decrease in albuminuria and renal fibrosis and restored glomerular nephrin expression. Administration of Ac-SDKP, in addition to ramipril, further reduced renal fibrosis with respect to ramipril alone, while it did not improve the antiproteinuric effect of ramipril. Ac-SDKP administration reduces renal fibrosis in diabetic nephropathy. Addition of Ac-SDKP to ACE inhibition therapy improves the reduction of renal fibrosis with respect to ACE inhibition alone, suggesting a beneficial effect of this pharmacological association in diabetic nephropathy.
Mechanoreceptors and chemoreceptors have been identified inside the kidney, but their functional ... more Mechanoreceptors and chemoreceptors have been identified inside the kidney, but their functional role is still largely unclear. The aim of this study was to investigate whether changes in urine output could modify the discharge rate of renal afferent fibers. Experiments were performed in anesthetized cats in which afferent renal nerve activity (ARNA) was recorded by standard electrophysiological techniques from a centrally cut renal nerve. Arterial pressure, renal blood flow velocity, urine flow rate, and renal pelvic pressure were also measured. Three diuretic maneuvers were tested in the same cat: intravenous administration of physiological saline (8 to 13 mL/min for 2 minutes), furosemide (1 mg/kg), and atrial natriuretic peptide (ANP, 1 microgram/kg). The three maneuvers increased urine flow rate and pelvic pressure, respectively, 137.0 +/- 20.6% and 136.8 +/- 21.1% (saline), 148.6 +/- 31.7% and 139.6 +/- 43.5% (furosemide), and 75.9 +/- 7.9% and 62.1 +/- 21.2% (ANP) at the time...
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