Proceedings of the 19th Annual International Conference of the IEEE Engineering in Medicine and Biology Society. 'Magnificent Milestones and Emerging Opportunities in Medical Engineering' (Cat. No.97CH36136)
... Bruce C. Wheeler*#, Darren W. Branch*, Joseph M. Carey", James A. Weyhenmeyer-and Gregor... more ... Bruce C. Wheeler*#, Darren W. Branch*, Joseph M. Carey", James A. Weyhenmeyer-and Gregory J. Brewer+ *Beckman Institute, Univ. Illinois at Urbana-Champaign, 405 N. Mathews, Urbana IL 61801 -Cell & Structural Biol. Dept., Univ. ...
The biosynthesis of angiotensin II-like peptide was measured in primary cultured brain cells from... more The biosynthesis of angiotensin II-like peptide was measured in primary cultured brain cells from the fetal rat. Cells from the whole brains of 20-day gestational age Sprague-Dawley rats were dissociated by mild trypsinization and grown for 5 days in supplemented (serum-free) medium prior to experimental analysis. The time-dependent incorporation of [3H]proline into newly synthesized angiotensin II-like peptide was measured by radioimmunoassay using specific angiotensin II antisera. Analysis of radioimmunoassay data revealed an increase in the amount of tritium-labeled angiotensin II in the crude extract of the brain cells during the first 24 h in culture. The chromatographic character of the angiotensin II-like peptide was further identified by high pressure liquid chromatography. Elution profiles for newly synthesized angiotensin II were identical to those profiles generated for [3H]angiotensin II and nonradiolabeled angiotensin II standards. To determine the bioactivity of the angiotensin II-like peptide, fractions of the column-purified peptide were injected into the region of the rat lateral ventricle via an indwelling cannula. Systolic pressure increased up to 20 mm Hg depending upon the amount of peptide injected. These data clearly support the existence of an endogenous renin-angiotensin system is dissociated brain cell cultures from the fetal rat, and provide an experimental model for further analysis of the regulatory mechanisms of angiotensin II synthesis.
Clinical and Experimental Hypertension. Part A: Theory and Practice, 1990
Dahl salt-sensitive rats are inbred on the basis of their tendency to develop hypertension when p... more Dahl salt-sensitive rats are inbred on the basis of their tendency to develop hypertension when placed on a high salt diet. The present study investigated the effects of chronic dietary tryptophan (trp) at 50 g/kg food on the development of hypertension in these animals under conditions of both normal and elevated dietary salt. Dietary trp attenuated the development of hypertension in inbred Dahl salt-sensitive (DS/JR) rats and had no effect upon the patterns of development of systolic blood pressures in the normotensive controls, the inbred Dahl salt-resistant (DR/JR) rat and the outbred parental Sprague Dawley (SD) rat. Cardiac hypertrophy, which is associated with Dahl salt-induced hypertension, was blocked by the high trp diet. Further work will be necessary to elucidate the mechanisms by which dietary trp protected against the development of hypertension and cardiac hypertrophy in DS/JR rats.
Journal of Pharmacology and Experimental Therapeutics
Cardiovascular responses after the central blockade of the brain angiotensin system with peptide ... more Cardiovascular responses after the central blockade of the brain angiotensin system with peptide or nonpeptide angiotensin II analogs in conscious, freely moving hypertensive Dahl salt-sensitive (DS/JR) rats were measured. Four-week-old animals were maintained on an 8% salt diet until experimentation at 7 weeks of age. At the time of experimentation, mean arterial pressures were 176 +/- 6 mm Hg. The i.c.v. administration of 20 micrograms of the peptide analog sarcosine1, threonine8-angiotensin II (sarthran) resulted in a significant bradycardic response (approximately 17% decrease in H.R. peaking at 8 min after injection) without a significant change in blood pressure. Central administration of the AT1 antagonist losartan (10 micrograms) or of the AT2 antagonist PD 123319 (10 micrograms) was without effect. The peptide and nonpeptide analogs differed in their ability to inhibit central angiotensin II (10 ng)-induced pressor and dipsogenic responses. PD 123319 (10 micrograms) had no effect on the pressor and dipsogenic responses, whereas losartan (10 micrograms) and sarthran (20 micrograms) inhibited both responses for 85 +/- 17 and 29 +/- 3 min, respectively. The effect of preblocking either the AT1 or the AT2 receptors on the sarthran-induced bradycardia was also determined. Preblocking with either losartan (10 micrograms) or PD 123319 (10 micrograms) inhibited the bradycardic response by approximately 45%, which suggests that both receptor subtypes are involved in the central cardiovascular responses in the DS/JR rat and that, because it was attenuated by pure antagonists, the response to sarthran may be mediated by its agonist actions.(ABSTRACT TRUNCATED AT 250 WORDS)
Proceedings of 18th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 1997
Abstract Our goal is the reliable synthesis of patterned living neural networks. To assess rapidl... more Abstract Our goal is the reliable synthesis of patterned living neural networks. To assess rapidly the qualities of candidate substrates we use the B104 neuroblastoma cell line with and without the differentiating agent dibutyrylcyclicAMP (DBcAMP). B104 cells prefer, in ...
Recent evidence has demonstrated that dissociated fetal rat brain cells in culture synthesize an ... more Recent evidence has demonstrated that dissociated fetal rat brain cells in culture synthesize an angiotensin II (ANG II)-like peptide that shares common properties with authentic ANG II, suggesting that brain has a complete renin angiotensin system that is independent of peripheral substrates. Although ANG II has been postulated to function as a neurotransmitter/neuromodulator, the release of ANG II from presynaptic nerve terminals has not been established. To investigate the mechanism of ANG II release, brain cells from 20-day gestational age Sprague-Dawley rats were dissociated by mild trypsinization and grown in culture. The cells were maintained in serum-free medium for 5 days prior to experimental analysis. Cultured brain cells were challenged with 59 mM KCl in the presence or absence of 5 mM CaCl2, and the incubation medium was measured for the release of ANG II by radioimmunoassay and high-performance liquid chromatography. The data demonstrate that K+ stimulation results in ...
Search by Subject Search using Medical Subject Headings (< b> MeSH&... more Search by Subject Search using Medical Subject Headings (< b> MeSH</b>), a controlled vocabulary for indexing life sciences content.< br/> Note that some records do not have MeSH. These include Patents and the latest PubMed and PubMed Central records.
Proceedings of the 19th Annual International Conference of the IEEE Engineering in Medicine and Biology Society. 'Magnificent Milestones and Emerging Opportunities in Medical Engineering' (Cat. No.97CH36136)
... Bruce C. Wheeler*#, Darren W. Branch*, Joseph M. Carey", James A. Weyhenmeyer-and Gregor... more ... Bruce C. Wheeler*#, Darren W. Branch*, Joseph M. Carey", James A. Weyhenmeyer-and Gregory J. Brewer+ *Beckman Institute, Univ. Illinois at Urbana-Champaign, 405 N. Mathews, Urbana IL 61801 -Cell & Structural Biol. Dept., Univ. ...
The biosynthesis of angiotensin II-like peptide was measured in primary cultured brain cells from... more The biosynthesis of angiotensin II-like peptide was measured in primary cultured brain cells from the fetal rat. Cells from the whole brains of 20-day gestational age Sprague-Dawley rats were dissociated by mild trypsinization and grown for 5 days in supplemented (serum-free) medium prior to experimental analysis. The time-dependent incorporation of [3H]proline into newly synthesized angiotensin II-like peptide was measured by radioimmunoassay using specific angiotensin II antisera. Analysis of radioimmunoassay data revealed an increase in the amount of tritium-labeled angiotensin II in the crude extract of the brain cells during the first 24 h in culture. The chromatographic character of the angiotensin II-like peptide was further identified by high pressure liquid chromatography. Elution profiles for newly synthesized angiotensin II were identical to those profiles generated for [3H]angiotensin II and nonradiolabeled angiotensin II standards. To determine the bioactivity of the angiotensin II-like peptide, fractions of the column-purified peptide were injected into the region of the rat lateral ventricle via an indwelling cannula. Systolic pressure increased up to 20 mm Hg depending upon the amount of peptide injected. These data clearly support the existence of an endogenous renin-angiotensin system is dissociated brain cell cultures from the fetal rat, and provide an experimental model for further analysis of the regulatory mechanisms of angiotensin II synthesis.
Clinical and Experimental Hypertension. Part A: Theory and Practice, 1990
Dahl salt-sensitive rats are inbred on the basis of their tendency to develop hypertension when p... more Dahl salt-sensitive rats are inbred on the basis of their tendency to develop hypertension when placed on a high salt diet. The present study investigated the effects of chronic dietary tryptophan (trp) at 50 g/kg food on the development of hypertension in these animals under conditions of both normal and elevated dietary salt. Dietary trp attenuated the development of hypertension in inbred Dahl salt-sensitive (DS/JR) rats and had no effect upon the patterns of development of systolic blood pressures in the normotensive controls, the inbred Dahl salt-resistant (DR/JR) rat and the outbred parental Sprague Dawley (SD) rat. Cardiac hypertrophy, which is associated with Dahl salt-induced hypertension, was blocked by the high trp diet. Further work will be necessary to elucidate the mechanisms by which dietary trp protected against the development of hypertension and cardiac hypertrophy in DS/JR rats.
Journal of Pharmacology and Experimental Therapeutics
Cardiovascular responses after the central blockade of the brain angiotensin system with peptide ... more Cardiovascular responses after the central blockade of the brain angiotensin system with peptide or nonpeptide angiotensin II analogs in conscious, freely moving hypertensive Dahl salt-sensitive (DS/JR) rats were measured. Four-week-old animals were maintained on an 8% salt diet until experimentation at 7 weeks of age. At the time of experimentation, mean arterial pressures were 176 +/- 6 mm Hg. The i.c.v. administration of 20 micrograms of the peptide analog sarcosine1, threonine8-angiotensin II (sarthran) resulted in a significant bradycardic response (approximately 17% decrease in H.R. peaking at 8 min after injection) without a significant change in blood pressure. Central administration of the AT1 antagonist losartan (10 micrograms) or of the AT2 antagonist PD 123319 (10 micrograms) was without effect. The peptide and nonpeptide analogs differed in their ability to inhibit central angiotensin II (10 ng)-induced pressor and dipsogenic responses. PD 123319 (10 micrograms) had no effect on the pressor and dipsogenic responses, whereas losartan (10 micrograms) and sarthran (20 micrograms) inhibited both responses for 85 +/- 17 and 29 +/- 3 min, respectively. The effect of preblocking either the AT1 or the AT2 receptors on the sarthran-induced bradycardia was also determined. Preblocking with either losartan (10 micrograms) or PD 123319 (10 micrograms) inhibited the bradycardic response by approximately 45%, which suggests that both receptor subtypes are involved in the central cardiovascular responses in the DS/JR rat and that, because it was attenuated by pure antagonists, the response to sarthran may be mediated by its agonist actions.(ABSTRACT TRUNCATED AT 250 WORDS)
Proceedings of 18th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 1997
Abstract Our goal is the reliable synthesis of patterned living neural networks. To assess rapidl... more Abstract Our goal is the reliable synthesis of patterned living neural networks. To assess rapidly the qualities of candidate substrates we use the B104 neuroblastoma cell line with and without the differentiating agent dibutyrylcyclicAMP (DBcAMP). B104 cells prefer, in ...
Recent evidence has demonstrated that dissociated fetal rat brain cells in culture synthesize an ... more Recent evidence has demonstrated that dissociated fetal rat brain cells in culture synthesize an angiotensin II (ANG II)-like peptide that shares common properties with authentic ANG II, suggesting that brain has a complete renin angiotensin system that is independent of peripheral substrates. Although ANG II has been postulated to function as a neurotransmitter/neuromodulator, the release of ANG II from presynaptic nerve terminals has not been established. To investigate the mechanism of ANG II release, brain cells from 20-day gestational age Sprague-Dawley rats were dissociated by mild trypsinization and grown in culture. The cells were maintained in serum-free medium for 5 days prior to experimental analysis. Cultured brain cells were challenged with 59 mM KCl in the presence or absence of 5 mM CaCl2, and the incubation medium was measured for the release of ANG II by radioimmunoassay and high-performance liquid chromatography. The data demonstrate that K+ stimulation results in ...
Search by Subject Search using Medical Subject Headings (< b> MeSH&... more Search by Subject Search using Medical Subject Headings (< b> MeSH</b>), a controlled vocabulary for indexing life sciences content.< br/> Note that some records do not have MeSH. These include Patents and the latest PubMed and PubMed Central records.
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