You are in the accessibility menu

Please use this identifier to cite or link to this item:
Nitric oxide modulates the cardiovascular effects elicited by acetylcholine in the NTS of awake rats
  • Universidade Federal de São Paulo (UNIFESP)
  • Universidade Estadual Paulista (UNESP)
  • Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
  • Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
  • Programa de Apoio aos Núcleos de Excelência (PRONEX)
da Silva LG, Rodrigues Dias AC, Furlan E, Colombari E. Nitric oxide modulates the cardiovascular effects elicited by acetylcholine in the NTS of awake rats. Am J Physiol Regul Integr Comp Physiol 295: R1774-R1781, 2008. First published September 24, 2008; doi:10.1152/ajpregu.00559.2007.-Microinjection of acetylcholine chloride (ACh) in the nucleus of the solitary tract (NTS) of awake rats caused a transient and dose-dependent hypotension and bradycardia. Because it is known that cardiovascular reflexes are affected by nitric oxide (NO) produced in the NTS, we investigated whether these ACh-induced responses depend on NO in the NTS. Responses to ACh (500 pmol in 100 nl) were strongly reduced by ipsilateral microinjection of the NOS inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME; 10 nmol in 100 nl) in the NTS: mean arterial pressure (MAP) fell by 50 +/- 5 mmHg before L-NAME to 9 +/- 4 mmHg, 10 min after L-NAME, and HR fell by 100 +/- 26 bpm before L-NAME to 20 +/- 10 bpm, 10 min after L-NAME (both P < 0.05). Microinjection of the selective inhibitor of neuronal nitric oxide synthase (nNOS), 1-(2-trifluoromethylphenyl) imidazole (TRIM; 13.3 nmol in 100 nl), in the NTS also reduced responses to ACh: MAP fell from 42 +/- 3 mmHg before TRIM to 27 +/- 6 mmHg, 10 min after TRIM (P < 0.05). TRIM also tended to reduce ACh-induced bradycardia, but this effect was not statistically significant. ACh-induced hypotension and bradycardia returned to control levels 30-45 min after NOS inhibition. Control injections with D-NAME and saline did not affect resting values or the response to ACh. In conclusion, injection of ACh into the NTS of conscious rats induces hypotension and bradycardia, and these effects may be mediated at least partly by NO produced in NTS neurons.
Issue Date: 
American Journal of Physiology-regulatory Integrative and Comparative Physiology. Bethesda: Amer Physiological Soc, v. 295, n. 6, p. R1774-R1781, 2008.
Time Duration: 
Amer Physiological Soc
  • cholinergic transmission
  • nitric oxide synthase inhibition
  • nucleus of the solitary tract
  • cardiovascular control
Access Rights: 
Acesso restrito
Appears in Collections:Artigos, TCCs, Teses e Dissertações da Unesp

There are no files associated with this item.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.