Time course of the hemodynamic responses to aortic depressor nerve stimulation in conscious spontaneously hypertensive rats


Autoria(s): Durand, M. T.; Mota, A. L.; Barale, A. R.; Castania, J. A.; Fazan, R., Jr.; Salgado, H. C.
Contribuinte(s)

UNIVERSIDADE DE SÃO PAULO

Data(s)

30/10/2013

30/10/2013

02/08/2013

Resumo

The time to reach the maximum response of arterial pressure, heart rate and vascular resistance (hindquarter and mesenteric) was measured in conscious male spontaneously hypertensive (SHR) and normotensive control rats (NCR; Wistar; 18-22 weeks) subjected to electrical stimulation of the aortic depressor nerve (ADN) under thiopental anesthesia. The parameters of stimulation were 1 mA intensity and 2 ms pulse length applied for 5 s, using frequencies of 10, 30, and 90 Hz. The time to reach the hemodynamic responses at different frequencies of ADN stimulation was similar for SHR (N = 15) and NCR (N = 14); hypotension = NCR (4194 +/- 336 to 3695 +/- 463 ms) vs SHR ( 3475 +/- 354 to 4494 +/- 300 ms); bradycardia = NCR (1618 +/- 152 to 1358 +/- 185 ms) vs SHR (1911 +/- 323 to 1852 +/- 431 ms), and the fall in hindquarter vascular resistance = NCR (6054 +/- 486 to 6550 +/- 847 ms) vs SHR (4849 +/- 918 to 4926 +/- 646 ms); mesenteric = NCR (5574 +/- 790 to 5752 +/- 539 ms) vs SHR (5638 +/- 648 to 6777 +/- 624 ms). In addition, ADN stimulation produced baroreflex responses characterized by a faster cardiac effect followed by a vascular effect, which together contributed to the decrease in arterial pressure. Therefore, the results indicate that there is no alteration in the conduction of the electrical impulse after the site of baroreceptor mechanical transduction in the baroreflex pathway (central and/or efferent) in conscious SHR compared to NCR.

FAPESP

FAPESP [02/09406-5]

CNPq

CNPq [134480/2006-6]

CAPES

CAPES [1681/07]

Identificador

BRAZILIAN JOURNAL OF MEDICAL AND BIOLOGICAL RESEARCH, SAO PAULO, v. 45, n. 5, supl., Part 3, pp. 444-449, MAY, 2012

0100-879X

http://www.producao.usp.br/handle/BDPI/36732

10.1590/S0100-879X2012007500032

http://dx.doi.org/10.1590/S0100-879X2012007500032

Idioma(s)

eng

Publicador

ASSOC BRAS DIVULG CIENTIFICA

SAO PAULO

Relação

BRAZILIAN JOURNAL OF MEDICAL AND BIOLOGICAL RESEARCH

Direitos

openAccess

Copyright ASSOC BRAS DIVULG CIENTIFICA

Palavras-Chave #ELECTRICAL STIMULATION #ARTERIAL PRESSURE #AORTIC DEPRESSOR NERVE #BAROREFLEX #SPONTANEOUSLY HYPERTENSIVE RATS #VASCULAR TONE #HEART-RATE REFLEX #ELECTRICAL-STIMULATION #SYMPATHETIC ACTIVITY #BAROREFLEX #VAGAL #SENSITIVITY #ACTIVATION #NEURONS #FIBERS #SYSTEM #BIOLOGY #MEDICINE, RESEARCH & EXPERIMENTAL
Tipo

article

original article

publishedVersion