Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/196766
Type: Artigo de periódico
Title: Dissociation Of Blood Pressure And Sympathetic Activation Of Renin Release In Sinoaortic-denervated Rats.
Author: Krieger, Marta H
Moreira, Edson D
Oliveira, Edilamar M
Oliveira, Vera L L
Krieger, Eduardo M
Krieger, Jose E
Abstract: 1. Blood pressure (BP) and heart rate (HR) increase 6 and 24 h after sinoaortic baroreceptor denervation (SAD), whereas plasma renin activity (PRA) and renal renin mRNA levels remain unchanged. We postulated that a simultaneous rise in BP could offset the expected activation of renin associated with an increased renal sympathetic discharge secondary to SAD. 2. To test this hypothesis, the increase in BP associated with the onset of SAD was prevented by a continuous infusion of sodium nitroprusside (SNP; 30 microg/kg per h). Changes were measured in five groups of conscious adult male Wistar rats: (i) sham; (ii) SAD; (iii) SAD rats in which the BP was prevented from increasing by infusion of SNP; (iv) sham rats in which the BP was increased by 30% by infusion of phenylephrine (PE; 1.5-2.0 mL/h); and (v) SNP + PE for 3 h by infusion as above. 3. As expected, BP and heart rate (HR) increased significantly following SAD compared with sham rats (152 +/- 4 vs 116 +/- 3 mmHg, respectively, for BP and 503 +/- 6 vs 345 +/- 13 b.p.m., respectively for HR; n = 5; P < 0.05) but remained unchanged when SNP was infused for 3 h (106 +/- 1 mmHg and 455 +/- 9 b.p.m., respectively; n = 5; P < 0.05). 4. Similarly, BP and HR increased with PE infusion compared with PE + SNP (138 +/- 9.9 vs 113 +/- 2.3 mmHg for BP, respectively, and 325 +/- 9 vs 423 +/- 18 b.p.m. for HR, respectively; n = 5; P < 0.05). 5. Plasma renin activity remained unchanged in SAD compared with sham rats (1.67 +/- 0.35 vs 1.05 +/- 0.17 ng angiotensin (Ang) I/mL per h), but increased significantly when hypertension was prevented (5.86 +/- 0.77 ng AngI/mL per h; n = 5; P < 0.05). Renin mRNA levels in the kidneys were unchanged in all groups. 6. These results show that an elevation in BP appears to offset increased renal sympathetic discharge with no change in PRA.
Subject: Angiotensins
Animals
Aorta
Baroreflex
Blood Pressure
Carotid Sinus
Denervation
Gene Expression Regulation
Heart Rate
Kidney
Male
Nitroprusside
Peptidyl-dipeptidase A
Phenylephrine
Pressoreceptors
Rna, Messenger
Rats
Rats, Wistar
Renin
Renin-angiotensin System
Time Factors
Vasoconstrictor Agents
Vasodilator Agents
Citation: Clinical And Experimental Pharmacology & Physiology. v. 33, n. 5-6, p. 471-6
Rights: fechado
Identifier DOI: 10.1111/j.1440-1681.2006.04389.x
Address: http://www.ncbi.nlm.nih.gov/pubmed/16700880
Appears in Collections:Unicamp - Artigos e Outros Documentos

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