This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Peotta, V. A. Articles by Meyrelles, S. S. Search for Related Content PubMed PubMed Citation Articles by Peotta, V. A. Articles by Meyrelles, S. S. Related Collections Animal models of human disease Hypertension - basic studies Autonomic, reflex, and neurohumoral control of circulation

(Hypertension. 2001;38:555.)
© 2001 American Heart Association, Inc.

Neurogenic Factors

Cardiovascular Neural Reflexes in L-NAME–Induced Hypertension in Mice

Veronica A. Peotta; Elisardo C. Vasquez; Silvana S. Meyrelles

Physiological Sciences Graduate Program, Biomedical Center, Federal University of Espirito Santo, and Health Sciences College (Emescam), Vitoria, ES, Brazil.

Correspondence to Silvana S. Meyrelles, PhD, Pos-Graduacao Ciencias Fisiologicas, CBM, UFES, Av. Marechal Campos 1468, Vitoria, ES 29040-090, Brazil. E-mail: meyrelle.vix{at}zaz.com.br

Abstract

Abstract—— The mouse is the most used animal for studying the genetic basis of cardiovascular diseases. However, the mechanisms of regulation of cardiovascular function in this animal are not yet well understood. The goal of this study was to evaluate the baroreflex, the Bezold-Jarisch cardiopulmonary reflex (BJR), and the chemoreflex in mice with hypertension induced by inhibition of NO using N-nitro-L-arginine-methyl ester (L-NAME). Basal mean arterial pressure (MAP) measured under anesthesia (urethane, 1 mg/g IP) was significantly higher in L-NAME (400 µg/g IP for 7 days)–treated (HT) mice (n=7) compared with vehicle-treated (NT; n=10) animals (126±9 versus 79±2 mm Hg) without differences in heart rate (HR). Baroreflex sensitivity, evaluated using phenylephrine (1 µg/g IV) was enhanced in HT mice compared with NT mice (-9.8±1.4 versus -4.9±0.5 bpm/mm Hg). The BJR, induced by phenylbiguanide (40 ng/g IV), was significantly attenuated in HT animals (MAP, -13±5%; HR, -39±6%) compared with NT animals (MAP, -38±5%; HR, -66±2%). The chemoreflex, induced by potassium cyanide (0.26 µg/g IV), was significantly attenuated in HT animals (MAP, +14±4%; HR, -8±2%) compared with NT animals (MAP, +29±4%; HR, -15±4%). As has been observed in rats, chronic inhibition of NO synthase in mice results in arterial hypertension. Enhancement of baroreflex sensitivity and attenuation of BJR and chemoreflex seem to be mainly caused by inhibition of NO synthesis because individual analyses did not show positive correlation between changes in these reflexes and MAP levels in the HT group.

Key Words: hypertension, experimental • mice • L-NAME • baroreflex • reflex

This article has been cited by other articles:

				J. R. Gayen, Y. Gu, D. T. O'Connor, and S. K. Mahata Global Disturbances in Autonomic Function Yield Cardiovascular Instability and Hypertension in the Chromogranin A Null Mouse Endocrinology, November 1, 2009; 150(11): 5027 - 5035. [Abstract] [Full Text] [PDF]

				V. A. Braga, M. A. Burmeister, R. V. Sharma, and R. L. Davisson Cardiovascular responses to peripheral chemoreflex activation and comparison of different methods to evaluate baroreflex gain in conscious mice using telemetry Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2008; 295(4): R1168 - R1174. [Abstract] [Full Text] [PDF]

				M. Obst, V. Gross, J. Janke, M. Wellner, W. Schneider, and F. C. Luft Pressure Natriuresis in AT2 Receptor-Deficient Mice with L-NAME Hypertension J. Am. Soc. Nephrol., February 1, 2003; 14(2): 303 - 310. [Abstract] [Full Text] [PDF]

				X. Ma, F. M. Abboud, and M. W. Chapleau Analysis of afferent, central, and efferent components of the baroreceptor reflex in mice Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2002; 283(5): R1033 - R1040. [Abstract] [Full Text] [PDF]

				J. Lorita, N. Escalona, S. Faraudo, M. Soley, and I. Ramirez Effects of epidermal growth factor on epinephrine-stimulated heart function in rodents Am J Physiol Heart Circ Physiol, November 1, 2002; 283(5): H1887 - H1895. [Abstract] [Full Text] [PDF]

				V. Gross, R. Plehm, J. Tank, J. Jordan, A. Diedrich, M. Obst, and F. C. Luft Heart Rate Variability and Baroreflex Function in AT2 Receptor-Disrupted Mice Hypertension, August 1, 2002; 40(2): 207 - 213. [Abstract] [Full Text] [PDF]

				B. J. A. Janssen and J. F. M. Smits Autonomic control of blood pressure in mice: basic physiology and effects of genetic modification Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2002; 282(6): R1545 - R1564. [Abstract] [Full Text] [PDF]