|
|
||||||||
Departamentos de Fisiologia, Faculdade de Odontologia de Ribeirão Preto and Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, 14040-904 Ribeirão Preto, São Paulo, Brazil
Hypercapnia elicits hypothermia in a number
of vertebrates, but the mechanisms involved are not well understood. In
the present study, we assessed the participation of the nitric oxide
(NO) pathway in hypercapnia-induced hypothermia and hyperventilation by
means of NO synthase inhibition by using
N
-nitro-L-arginine
(L-NNA). Measurements of
ventilation, body temperature, and oxygen consumption were performed in
awake unrestrained rats before and after
L-NNA injection
(intraperitoneally) and L-NNA injection followed by hypercapnia (5%
CO2). Control animals received saline injections. L-NNA altered
the breathing pattern during the control situation but not during
hypercapnia. A significant (P < 0.05) drop in body temperature was measured after both
L-NNA (40 mg/kg) and 5%
inspired CO2, with a drop in
oxygen consumption in the first situation but not in the second.
Hypercapnia had no effect on
L-NNA-induced hypothermia. The
ventilatory response to hypercapnia was not changed by
L-NNA, even though
L-NNA caused a drop in body
temperature. The present data indicate that the two responses elicited
by hypercapnia, i.e., hyperventilation and hypothermia, do not share NO
as a common mediator. However, the
L-arginine-NO pathway
participates, although in an unrelated way, in respiratory function and
thermoregulation.
body temperature; ventilation; carbon dioxide
This article has been cited by other articles:
![]() |
M. P. Walsh and J. M. Marshall The early effects of chronic hypoxia on the cardiovascular system in the rat: role of nitric oxide J. Physiol., August 15, 2006; 575(1): 263 - 275. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Choi, L. A. Hoffman, G. W. Rodway, and J. M. Sethi Markers of lung disease in exhaled breath: nitric oxide. Biol Res Nurs, April 1, 2006; 7(4): 241 - 255. [Abstract] [PDF] |
||||
![]() |
E. R. Price, F. Han, T. E. Dick, and K. P. Strohl 7-Nitroindazole and posthypoxic ventilatory behavior in the A/J and C57BL/6J mouse strains J Appl Physiol, September 1, 2003; 95(3): 1097 - 1104. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Subramanian, B. Erokwu, F. Han, T. E. Dick, and K. P. Strohl L-NAME differentially alters ventilatory behavior in Sprague-Dawley and Brown Norway rats J Appl Physiol, September 1, 2002; 93(3): 984 - 989. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. B. Harris, R. J. A. Wilson, K. Vasilakos, B. E. Taylor, and J. E. Remmers Central respiratory activity of the tadpole in vitro brain stem is modulated diversely by nitric oxide Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2002; 283(2): R417 - R428. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. H. Gargaglioni and L. G. S. Branco Effect of nitric oxide in the nucleus isthmi on the hypoxic and hypercarbic drive to breathing of toads Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2001; 281(1): R338 - R345. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. A. Steiner, E. C. Carnio, and L. G. S. Branco Role of neuronal nitric oxide synthase in hypoxia-induced anapyrexia in rats J Appl Physiol, September 1, 2000; 89(3): 1131 - 1136. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. G. S. Branco, A. A. Steiner, G. J. Tattersall, and S. C. Wood Role of adenosine in the hypoxia-induced hypothermia of toads Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2000; 279(1): R196 - R201. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. D. Kline, T. Yang, D. R. D. Premkumar, A. J. Thomas, and N. R. Prabhakar Blunted respiratory responses to hypoxia in mutant mice deficient in nitric oxide synthase-3 J Appl Physiol, April 1, 2000; 88(4): 1496 - 1508. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. C. Almeida, E. C. Carnio, and L. G. S. Branco Role of nitric oxide in hypoxia inhibition of fever J Appl Physiol, December 1, 1999; 87(6): 2186 - 2190. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Gautier and C. Murariu Role of nitric oxide in hypoxic hypometabolism in rats J Appl Physiol, July 1, 1999; 87(1): 104 - 110. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. A. Steiner, E. C. Carnio, J. Antunes-Rodrigues, and L. G. S. Branco Role of nitric oxide in systemic vasopressin-induced hypothermia Am J Physiol Regulatory Integrative Comp Physiol, October 1, 1998; 275(4): R937 - R941. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |