It remains unclear whether sickle cell trait (SCT) should be considered a risk factor during inte... more It remains unclear whether sickle cell trait (SCT) should be considered a risk factor during intense physical activity. By triggering the polymerization-sickling-vaso-occlusion cascade, lactate accumulation-associated acidosis in response to high-intensity exercise is believed to be one of the causes of complications. However, our understanding of lactate metabolism in response to high-intensity exercise in SCT carriers is incomplete. Thirty male SCT carriers (n = 15) and healthy subjects (n = 15) with and without α-thalassemia performed a 2-min high-intensity exercise. Blood and muscle lactate concentrations were measured at exercise completion. Time courses of blood lactate and glucose concentrations were followed during the subsequent recovery. Additional biochemical analyses were performed on biopsies of the vastus lateralis muscle. SCT was associated with lower blood and muscle lactate concentrations in response to the short high-intensity exercise. Compared to controls, the mu...
The aim of the study was to examine the effects of endurance exercise on circulating vascular cel... more The aim of the study was to examine the effects of endurance exercise on circulating vascular cell adhesion molecule-1 (sVCAM-1) and intercellular adhesion molecule-1 (sICAM-1) in sickle cell trait (SCT) athletes with or without alpha-thalassemia. Five athletes with SCT, 7 athletes with both SCT and alpha-thalassemia (SCTAT) and 8 control athletes (CONT) performed an incremental test on cycloergometer followed 72 hours later by a 60-min endurance exercise with a workload set at 70% P(peak) (peak power). We assessed levels of sICAM-1, sVCAM-1 and TNF-alpha at rest, immediately after endurance exercise and 1, 2, and 24 hours of recovery. Although, CONT and SCTAT groups exhibited similar basal plasma levels of adhesion molecules and TNF-alpha, SCT group had higher sVCAM-1 basal concentrations. No significant variation in sVCAM-1, sICAM-1 and TNF-alpha was measured following endurance exercise. Consequently, sVCAM-1 remained elevated in the SCT group after exercise and during the recovery period. In conclusion, our findings support the concept that SCT athletes might be at risk for microcirculatory disturbances, but these adhesive processes were not further impaired in response to endurance exercise. In addition, alpha-thalassemia co existing trait may be protective both at rest and after endurance exercise in SCT subjects.
Oxidative stress would play a role in the pathophysiology of sickle cell anemia (SCA). We tested ... more Oxidative stress would play a role in the pathophysiology of sickle cell anemia (SCA). We tested the impact of common SCA genetic modifiers (alpha-thalassemia, G6PD deficiency, HbF quantitative trait loci; QTL) and pro/antioxidant genes polymorphisms (SOD2 rs4880, XO rs207454, MPO rs233322) on oxidative stress biomarkers (AOPP, MDA, MPO, XO, MnSOD, CAT, GPx) and clinical severity in 301 Senegalese SCA hydroxyurea-free children at steady-state (median age 9.1 years, sex ratio H/F = 1.3). Plasma oxidative stress biomarkers were compared with those of a control group (AA). CAT activity, AOPP, and MDA levels were higher in SCA than in AA individuals while XO, GPX, and MnSOD activities were lower. The presence of alpha-thalassemia decreased MDA level and MPO activity but no effect of the HbF QTL or G6PD deficiency was observed. SCA children who experienced their first hospitalized complication before 3 years old had higher MnSOD and CAT activities than the other children while those with...
Oxidative stress is a key feature in the pathophysiology of sickle cell disease. Endurance traini... more Oxidative stress is a key feature in the pathophysiology of sickle cell disease. Endurance training has been shown to reduce oxidative stress in the heart and the liver of sickle mice. However, the effects of endurance training on skeletal muscles, which are major producers of reactive oxygen species during exercise, are currently unknown. The aim of this study was to evaluate the effect of sickle genotype on prooxidant/antioxidant response to individualized endurance training in skeletal muscles of sickle mice. Healthy and homozygous Townes sickle mice were divided into trained or sedentary groups. Maximal aerobic speed and V̇O2peak were determined using an incremental test on a treadmill. Trained mice ran at 40% to 60% of maximal aerobic speed, 1 h/day, 5 days/week for 8 weeks. Oxidative stress markers, prooxidant/antioxidant response, and citrate synthase enzyme activities were assessed in thegastrocnemius, in theplantaris, and in thesoleusmuscles. Maximal aerobic speed and V̇O2p...
This review focuses on the contribution of abnormal blood rheology in the pathophysiology of sick... more This review focuses on the contribution of abnormal blood rheology in the pathophysiology of sickle cell anemia (SCA). SCA is characterized by a reduction of red blood cell (RBC) deformability but this reduction is very heterogeneous among patients. Recent works have shown that patients with the lowest RBC deformability (measured by ektacytometry) have enhanced hemolysis and would be more prone to develop several complications such as priapism, leg ulcers and glomerulopathy. In contrast, patients with the highest deformability, and not under hydroxyurea therapy, seem to develop more frequently vaso-occlusive like events. Although less studied, RBC aggregation properties are very different between SCA and healthy individuals and it was demonstrated that increased RBC aggregates strength could be involved in some complications. Finally, several studies have established that the vascular system of SCA patients could not fully compensate any increase in blood viscosity because of the lo...
Oxidative stress and haemolysis-associated nitric oxide (NO) depletion plays a crucial role in th... more Oxidative stress and haemolysis-associated nitric oxide (NO) depletion plays a crucial role in the development of vasculopathy in sickle cell anaemia (SS). However it remains unknown whether oxidative stress and haemolysis levels influence vascular function in patients with sickle haemoglobin C disease (SC). Microvascular response to heat (using Laser Doppler flowmetry on finger), oxidative stress biomarkers, NO metabolites, endothelin-1 and haematological parameters were compared between patients with SS and SC. Vascular function, oxidative and nitrosative markers were also measured in healthy (AA) children. SS and SC had increased plasma advanced oxidation protein products (AOPP), malondialdehyde, plasma antioxidant activities and NO end products, compared to AA. SC had lower catalase activity compared to AA and SS. Haemolytic rate, glutathione peroxidase and nitrotyrosine concentrations were significantly increased in children with SS compared to SC and AA. SS and SC had impaired...
Sickle cell anaemia (SCA) is a severe hereditary haemoglobinopathy characterised by haemorheologi... more Sickle cell anaemia (SCA) is a severe hereditary haemoglobinopathy characterised by haemorheological abnormalities, which play a role in the occurrence of several acute and chronic clinical complications. While β(S) -haplotypes and alpha-thalassaemia modulate SCA clinical severity, their effects on blood rheology have been incompletely described. The aim of this study was to test the effects of these genetic modifiers on the haemorheological properties and clinical complication of children with SCA. Steady-state haemorheological profile, biological parameters, β(S) -haplotypes, alpha-globin status, vaso-occlusive crisis (VOC) and acute chest syndrome frequencies were analysed in 128 children (aged 5 to 18 years) with SCA. Patients with alpha-thalassaemia showed increased red blood cell (RBC) deformability and aggregation compared to those without. Median VOC rate was higher in patients with homozygous alpha-thalassaemia compared to those with a normal alpha genotype. Conversely, the...
Sickle cell disease (SCD) is the most common inherited disease in the world. Red blood cell sickl... more Sickle cell disease (SCD) is the most common inherited disease in the world. Red blood cell sickling, blood cell-endothelium adhesion, blood rheology abnormalities, intravascular haemolysis, and increased oxidative stress and inflammation contribute to the pathophysiology of SCD. Because acute intense exercise may alter these pathophysiological mechanisms, physical activity is usually contra-indicated in patients with SCD. However, recent studies in sickle-cell trait carriers and in a SCD mice model show that regular physical activity could decrease oxidative stress and inflammation, limit blood rheology alterations and increase nitric oxide metabolism. Therefore, supervised habitual physical activity may benefit patients with SCD. This article reviews the literature on the effects of acute and chronic exercise on the biological responses and clinical outcomes of patients with SCD.
Sickle cell disease is a class of hemoglobinopathy in humans, which is the most common inherited ... more Sickle cell disease is a class of hemoglobinopathy in humans, which is the most common inherited disease in the world. Although complications of sickle cell disease start from polymerization of red blood cells during its deoxygenating phase, the oxidative stress resulting from the biological processes associated with this disease (ischaemic and hypoxic injuries, hemolysis and inflammation) has been shown to contribute to its pathophysiology. It is widely known that chronic exercise reduces oxidative stress in healthy people, mainly via improvement of antioxidant enzyme efficiency. In addition, recent studies in other diseases, as well as in sickle cell trait carriers and in a mouse model of sickle cell disease, have shown that regular physical activity could decrease oxidative stress. The purpose of this review is to summarize the role of oxidative stress in sickle cell disease and the effects of acute and chronic exercise on the pro-oxidant/antioxidant balance in sickle cell trait and sickle cell disease.
In sickle cell disease, the factors involved in vasoocclusive crisis (VOC) include the sickling o... more In sickle cell disease, the factors involved in vasoocclusive crisis (VOC) include the sickling of red blood cells (RBC), abnormal blood rheology, inflammation, vascular adhesion, oxidative stress, coagulation, and vascular tone modulation. The aim of this study was to further characterize the molecular response of some factors involved in VOC by inducing a hypoxia/reoxygenation stress in sickle SAD mice. Results show that a hypoxia/reoxygenation stress in SAD mice can induce: (i) a decrease in reticulocytes count, and mean corpuscular volume along with an increase in lactate dehydrogenase (p = 0.07) and sickled cell proportion; (ii) a significant increase in lung VCAM-1, ICAM-1, IL-1β, ET-1, eNOS, and TF mRNA associated with an increase in VCAM-1 expression on lung endothelium; (iii) a rise in cardiac oxidative stress with increased lipid oxidation and decreased anti-oxidant enzyme activities, and (iv) an increase in plasma TNF-α and IL-6 and a decrease in plasma ET-1. In SAD mice,...
Oxidative stress plays a crucial role in sickle cell disease (SCD) physiopathology. Given that ch... more Oxidative stress plays a crucial role in sickle cell disease (SCD) physiopathology. Given that chronic physical activity is known to decrease reactive oxygen species (ROS) and increase nitric oxide (NO) bioavailability in healthy subjects and in patients with cardiovascular or inflammatory pathologies, modulating these factors involved in the severity of the pathology could also be beneficial in SCD. This study aimed to determine if 8 weeks of increased physical activity (PA) by voluntary wheel running affects the hypoxia/reoxygenation (H/R) responses by reducing oxidative stress and increasing NO synthesis in sickle SAD mice. Nitrite/nitrate (NOx) concentrations, NOS3 mRNA expression and phosphorylated-endothelial nitric oxide synthase immunostaining were increased in the lungs of the PA groups after H/R stress. Moreover, lipid peroxidation in the heart was decreased in PA SAD mice. The improvement of antioxidant activity at rest and the decrease in haemolysis may explain this redu...
It remains unclear whether habitual physical activity in sickle cell trait (SCT) carriers modulat... more It remains unclear whether habitual physical activity in sickle cell trait (SCT) carriers modulates the levels of resting and postexercise vascular adhesion and inflammatory molecules. Plasma levels of pro-inflammatory (interleukin (IL)-4, IL-5, IL-8, sCD40L, and tumor necrosis factor α) and anti-inflammatory (IL-10) cytokines and adhesion molecules (soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1), sP-selectin, or sE-selectin) were assessed at rest and in response to an incremental exercise to exhaustion in untrained (UT: no regular physical activity) and trained (T: soccer players, 8 h·wk minimum) SCT and control (CON) subjects (n = 8 per group; age = 23.5 ± 0.35 yr). sVCAM-1 levels were significantly higher in the UT-SCT group than that in T-SCT group (+43.5%) at rest, at the end, and at 1, 2, and 24 h after the end of the exercise. For the other molecules, no differences emerged among the groups at rest, but in response to exercise plasma, sICAM-1, sVCAM-1, sE-selectin, and sCD40L increased in all groups, and sP-selectin only increased in the UT group. All values that increased with the acute exercise returned to their respective baseline levels 1 h after the end of the exercise. A physically active lifestyle in SCT carriers may decrease endothelial activation and may limit the risk for vascular adhesion events in the microcirculation of SCT subjects.
To assess the effects of regular physical activity on muscle functional characteristics of carrie... more To assess the effects of regular physical activity on muscle functional characteristics of carriers of sickle cell trait (SCT), 39 untrained (U) and trained (T) hemoglobin (Hb)AA (CON) and SCT subjects (U-CON, n = 12; U-SCT, n = 8; T-CON, n = 10; and T-SCT, n = 9) performed a graded exercise and a time to exhaustion (Tex) test, and were subjected to a muscle biopsy. Maximal power, total work performed during Tex, citrate synthase and cytochrome c oxidase (COX) activities, respiratory chain complexes I and IV content, and capillary density (CD), diameter (COD), and surface area (CSA) were upregulated by the same proportion in T-CON and T-SCT compared with their untrained counterparts. These proportionally similar differences imply that the observed discrepancies between U-SCT and U-CON remained in the trained subjects. Specifically, both CD and COX remained and tended to remain lower, and both COD and CSA remained and tended to remain higher in T-SCT than in T-CON. Besides, carriers ...
It remains unclear whether sickle cell trait (SCT) should be considered a risk factor during inte... more It remains unclear whether sickle cell trait (SCT) should be considered a risk factor during intense physical activity. By triggering the polymerization-sickling-vaso-occlusion cascade, lactate accumulation-associated acidosis in response to high-intensity exercise is believed to be one of the causes of complications. However, our understanding of lactate metabolism in response to high-intensity exercise in SCT carriers is incomplete. Thirty male SCT carriers (n = 15) and healthy subjects (n = 15) with and without α-thalassemia performed a 2-min high-intensity exercise. Blood and muscle lactate concentrations were measured at exercise completion. Time courses of blood lactate and glucose concentrations were followed during the subsequent recovery. Additional biochemical analyses were performed on biopsies of the vastus lateralis muscle. SCT was associated with lower blood and muscle lactate concentrations in response to the short high-intensity exercise. Compared to controls, the mu...
The aim of the study was to examine the effects of endurance exercise on circulating vascular cel... more The aim of the study was to examine the effects of endurance exercise on circulating vascular cell adhesion molecule-1 (sVCAM-1) and intercellular adhesion molecule-1 (sICAM-1) in sickle cell trait (SCT) athletes with or without alpha-thalassemia. Five athletes with SCT, 7 athletes with both SCT and alpha-thalassemia (SCTAT) and 8 control athletes (CONT) performed an incremental test on cycloergometer followed 72 hours later by a 60-min endurance exercise with a workload set at 70% P(peak) (peak power). We assessed levels of sICAM-1, sVCAM-1 and TNF-alpha at rest, immediately after endurance exercise and 1, 2, and 24 hours of recovery. Although, CONT and SCTAT groups exhibited similar basal plasma levels of adhesion molecules and TNF-alpha, SCT group had higher sVCAM-1 basal concentrations. No significant variation in sVCAM-1, sICAM-1 and TNF-alpha was measured following endurance exercise. Consequently, sVCAM-1 remained elevated in the SCT group after exercise and during the recovery period. In conclusion, our findings support the concept that SCT athletes might be at risk for microcirculatory disturbances, but these adhesive processes were not further impaired in response to endurance exercise. In addition, alpha-thalassemia co existing trait may be protective both at rest and after endurance exercise in SCT subjects.
Oxidative stress would play a role in the pathophysiology of sickle cell anemia (SCA). We tested ... more Oxidative stress would play a role in the pathophysiology of sickle cell anemia (SCA). We tested the impact of common SCA genetic modifiers (alpha-thalassemia, G6PD deficiency, HbF quantitative trait loci; QTL) and pro/antioxidant genes polymorphisms (SOD2 rs4880, XO rs207454, MPO rs233322) on oxidative stress biomarkers (AOPP, MDA, MPO, XO, MnSOD, CAT, GPx) and clinical severity in 301 Senegalese SCA hydroxyurea-free children at steady-state (median age 9.1 years, sex ratio H/F = 1.3). Plasma oxidative stress biomarkers were compared with those of a control group (AA). CAT activity, AOPP, and MDA levels were higher in SCA than in AA individuals while XO, GPX, and MnSOD activities were lower. The presence of alpha-thalassemia decreased MDA level and MPO activity but no effect of the HbF QTL or G6PD deficiency was observed. SCA children who experienced their first hospitalized complication before 3 years old had higher MnSOD and CAT activities than the other children while those with...
Oxidative stress is a key feature in the pathophysiology of sickle cell disease. Endurance traini... more Oxidative stress is a key feature in the pathophysiology of sickle cell disease. Endurance training has been shown to reduce oxidative stress in the heart and the liver of sickle mice. However, the effects of endurance training on skeletal muscles, which are major producers of reactive oxygen species during exercise, are currently unknown. The aim of this study was to evaluate the effect of sickle genotype on prooxidant/antioxidant response to individualized endurance training in skeletal muscles of sickle mice. Healthy and homozygous Townes sickle mice were divided into trained or sedentary groups. Maximal aerobic speed and V̇O2peak were determined using an incremental test on a treadmill. Trained mice ran at 40% to 60% of maximal aerobic speed, 1 h/day, 5 days/week for 8 weeks. Oxidative stress markers, prooxidant/antioxidant response, and citrate synthase enzyme activities were assessed in thegastrocnemius, in theplantaris, and in thesoleusmuscles. Maximal aerobic speed and V̇O2p...
This review focuses on the contribution of abnormal blood rheology in the pathophysiology of sick... more This review focuses on the contribution of abnormal blood rheology in the pathophysiology of sickle cell anemia (SCA). SCA is characterized by a reduction of red blood cell (RBC) deformability but this reduction is very heterogeneous among patients. Recent works have shown that patients with the lowest RBC deformability (measured by ektacytometry) have enhanced hemolysis and would be more prone to develop several complications such as priapism, leg ulcers and glomerulopathy. In contrast, patients with the highest deformability, and not under hydroxyurea therapy, seem to develop more frequently vaso-occlusive like events. Although less studied, RBC aggregation properties are very different between SCA and healthy individuals and it was demonstrated that increased RBC aggregates strength could be involved in some complications. Finally, several studies have established that the vascular system of SCA patients could not fully compensate any increase in blood viscosity because of the lo...
Oxidative stress and haemolysis-associated nitric oxide (NO) depletion plays a crucial role in th... more Oxidative stress and haemolysis-associated nitric oxide (NO) depletion plays a crucial role in the development of vasculopathy in sickle cell anaemia (SS). However it remains unknown whether oxidative stress and haemolysis levels influence vascular function in patients with sickle haemoglobin C disease (SC). Microvascular response to heat (using Laser Doppler flowmetry on finger), oxidative stress biomarkers, NO metabolites, endothelin-1 and haematological parameters were compared between patients with SS and SC. Vascular function, oxidative and nitrosative markers were also measured in healthy (AA) children. SS and SC had increased plasma advanced oxidation protein products (AOPP), malondialdehyde, plasma antioxidant activities and NO end products, compared to AA. SC had lower catalase activity compared to AA and SS. Haemolytic rate, glutathione peroxidase and nitrotyrosine concentrations were significantly increased in children with SS compared to SC and AA. SS and SC had impaired...
Sickle cell anaemia (SCA) is a severe hereditary haemoglobinopathy characterised by haemorheologi... more Sickle cell anaemia (SCA) is a severe hereditary haemoglobinopathy characterised by haemorheological abnormalities, which play a role in the occurrence of several acute and chronic clinical complications. While β(S) -haplotypes and alpha-thalassaemia modulate SCA clinical severity, their effects on blood rheology have been incompletely described. The aim of this study was to test the effects of these genetic modifiers on the haemorheological properties and clinical complication of children with SCA. Steady-state haemorheological profile, biological parameters, β(S) -haplotypes, alpha-globin status, vaso-occlusive crisis (VOC) and acute chest syndrome frequencies were analysed in 128 children (aged 5 to 18 years) with SCA. Patients with alpha-thalassaemia showed increased red blood cell (RBC) deformability and aggregation compared to those without. Median VOC rate was higher in patients with homozygous alpha-thalassaemia compared to those with a normal alpha genotype. Conversely, the...
Sickle cell disease (SCD) is the most common inherited disease in the world. Red blood cell sickl... more Sickle cell disease (SCD) is the most common inherited disease in the world. Red blood cell sickling, blood cell-endothelium adhesion, blood rheology abnormalities, intravascular haemolysis, and increased oxidative stress and inflammation contribute to the pathophysiology of SCD. Because acute intense exercise may alter these pathophysiological mechanisms, physical activity is usually contra-indicated in patients with SCD. However, recent studies in sickle-cell trait carriers and in a SCD mice model show that regular physical activity could decrease oxidative stress and inflammation, limit blood rheology alterations and increase nitric oxide metabolism. Therefore, supervised habitual physical activity may benefit patients with SCD. This article reviews the literature on the effects of acute and chronic exercise on the biological responses and clinical outcomes of patients with SCD.
Sickle cell disease is a class of hemoglobinopathy in humans, which is the most common inherited ... more Sickle cell disease is a class of hemoglobinopathy in humans, which is the most common inherited disease in the world. Although complications of sickle cell disease start from polymerization of red blood cells during its deoxygenating phase, the oxidative stress resulting from the biological processes associated with this disease (ischaemic and hypoxic injuries, hemolysis and inflammation) has been shown to contribute to its pathophysiology. It is widely known that chronic exercise reduces oxidative stress in healthy people, mainly via improvement of antioxidant enzyme efficiency. In addition, recent studies in other diseases, as well as in sickle cell trait carriers and in a mouse model of sickle cell disease, have shown that regular physical activity could decrease oxidative stress. The purpose of this review is to summarize the role of oxidative stress in sickle cell disease and the effects of acute and chronic exercise on the pro-oxidant/antioxidant balance in sickle cell trait and sickle cell disease.
In sickle cell disease, the factors involved in vasoocclusive crisis (VOC) include the sickling o... more In sickle cell disease, the factors involved in vasoocclusive crisis (VOC) include the sickling of red blood cells (RBC), abnormal blood rheology, inflammation, vascular adhesion, oxidative stress, coagulation, and vascular tone modulation. The aim of this study was to further characterize the molecular response of some factors involved in VOC by inducing a hypoxia/reoxygenation stress in sickle SAD mice. Results show that a hypoxia/reoxygenation stress in SAD mice can induce: (i) a decrease in reticulocytes count, and mean corpuscular volume along with an increase in lactate dehydrogenase (p = 0.07) and sickled cell proportion; (ii) a significant increase in lung VCAM-1, ICAM-1, IL-1β, ET-1, eNOS, and TF mRNA associated with an increase in VCAM-1 expression on lung endothelium; (iii) a rise in cardiac oxidative stress with increased lipid oxidation and decreased anti-oxidant enzyme activities, and (iv) an increase in plasma TNF-α and IL-6 and a decrease in plasma ET-1. In SAD mice,...
Oxidative stress plays a crucial role in sickle cell disease (SCD) physiopathology. Given that ch... more Oxidative stress plays a crucial role in sickle cell disease (SCD) physiopathology. Given that chronic physical activity is known to decrease reactive oxygen species (ROS) and increase nitric oxide (NO) bioavailability in healthy subjects and in patients with cardiovascular or inflammatory pathologies, modulating these factors involved in the severity of the pathology could also be beneficial in SCD. This study aimed to determine if 8 weeks of increased physical activity (PA) by voluntary wheel running affects the hypoxia/reoxygenation (H/R) responses by reducing oxidative stress and increasing NO synthesis in sickle SAD mice. Nitrite/nitrate (NOx) concentrations, NOS3 mRNA expression and phosphorylated-endothelial nitric oxide synthase immunostaining were increased in the lungs of the PA groups after H/R stress. Moreover, lipid peroxidation in the heart was decreased in PA SAD mice. The improvement of antioxidant activity at rest and the decrease in haemolysis may explain this redu...
It remains unclear whether habitual physical activity in sickle cell trait (SCT) carriers modulat... more It remains unclear whether habitual physical activity in sickle cell trait (SCT) carriers modulates the levels of resting and postexercise vascular adhesion and inflammatory molecules. Plasma levels of pro-inflammatory (interleukin (IL)-4, IL-5, IL-8, sCD40L, and tumor necrosis factor α) and anti-inflammatory (IL-10) cytokines and adhesion molecules (soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1), sP-selectin, or sE-selectin) were assessed at rest and in response to an incremental exercise to exhaustion in untrained (UT: no regular physical activity) and trained (T: soccer players, 8 h·wk minimum) SCT and control (CON) subjects (n = 8 per group; age = 23.5 ± 0.35 yr). sVCAM-1 levels were significantly higher in the UT-SCT group than that in T-SCT group (+43.5%) at rest, at the end, and at 1, 2, and 24 h after the end of the exercise. For the other molecules, no differences emerged among the groups at rest, but in response to exercise plasma, sICAM-1, sVCAM-1, sE-selectin, and sCD40L increased in all groups, and sP-selectin only increased in the UT group. All values that increased with the acute exercise returned to their respective baseline levels 1 h after the end of the exercise. A physically active lifestyle in SCT carriers may decrease endothelial activation and may limit the risk for vascular adhesion events in the microcirculation of SCT subjects.
To assess the effects of regular physical activity on muscle functional characteristics of carrie... more To assess the effects of regular physical activity on muscle functional characteristics of carriers of sickle cell trait (SCT), 39 untrained (U) and trained (T) hemoglobin (Hb)AA (CON) and SCT subjects (U-CON, n = 12; U-SCT, n = 8; T-CON, n = 10; and T-SCT, n = 9) performed a graded exercise and a time to exhaustion (Tex) test, and were subjected to a muscle biopsy. Maximal power, total work performed during Tex, citrate synthase and cytochrome c oxidase (COX) activities, respiratory chain complexes I and IV content, and capillary density (CD), diameter (COD), and surface area (CSA) were upregulated by the same proportion in T-CON and T-SCT compared with their untrained counterparts. These proportionally similar differences imply that the observed discrepancies between U-SCT and U-CON remained in the trained subjects. Specifically, both CD and COX remained and tended to remain lower, and both COD and CSA remained and tended to remain higher in T-SCT than in T-CON. Besides, carriers ...
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Papers by Cyril Martin