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 Akemi Sato, M. Articles by Colombari, E. Search for Related Content PubMed PubMed Citation Articles by Akemi Sato, M. Articles by Colombari, E. Pubmed/NCBI databases Medline Plus Health Information High Blood Pressure

(Hypertension. 2001;38:560.)
© 2001 American Heart Association, Inc.

Neurogenic Factors

Lesions of the Commissural Nucleus of the Solitary Tract Reduce Arterial Pressure in Spontaneously Hypertensive Rats

Monica Akemi Sato; José Vanderlei Menani; Oswaldo Ubríaco Lopes; Eduardo Colombari

Department of Physiology, Universidade Federal de Sao Paulo, Escola Paulista de Medicina (M.A.S., O.U.L., E.C.), Sao Paulo, Brazil; and Department of Physiology and Pathology, Faculdade de Odontologia, Universidade Estadual Paulista-UNESP (J.V.M.), Araraquara, Brazil.

Correspondence to Eduardo Colombari, PhD, Department of Physiology, Universidade Federal de Sao Paulo-Escola Paulista de Medicina, 862 Botucatu St, 04023-060 Sao Paulo-SP, Brazil. E-mail colombari{at}fcr.epm.br

Abstract

Abstract—— It has been suggested that increased sympathetic activity and arterial chemoreceptors are important for the high blood pressure in spontaneously hypertensive rats (SHR). Electrolytic lesions of the commissural nucleus of the solitary tract (commNTS) abolish (1) the cardiovascular responses to chemoreflex activation with potassium cyanide (KCN) in normotensive rats and (2) the hypertension that follows acute aortic baroreceptor denervation in rats. Therefore, in this study we investigated the effects of electrolytic lesions of the commNTS on basal mean arterial pressure (MAP), baroreflex, and chemoreflex in SHR and in normotensive control Wistar-Kyoto (WKY) and Wistar rats. CommNTS lesions elicited a dramatic fall in MAP to normal levels during the period of study (from the first to fourth day following lesions) in SHR and almost no changes in WKY and Wistar rats. The pressor responses to chemoreflex activation with KCN tested in the days 1 and 4 after commNTS lesions were abolished in SHR and in normotensive strains. The reflex tachycardia induced by sodium nitroprusside was also attenuated in days 1 and 4 after commNTS lesions in SHR, WKY, and Wistar rats. The data suggest that the integrity of commNTS is important for the maintenance of high blood pressure in SHR and for the reflex responses dependent on sympathetic activation either in SHR or in normotensive strains.

Key Words: baroreceptors • chemoreceptors • solitary nucleus • rats, spontaneously hypertensive

This article has been cited by other articles:

				P. von Heinemann, O. Grauer, G. Schuierer, M. Ritzka, U. Bogdahn, B. Kaiser, and F. Schlachetzki Recurrent cardiac arrest caused by lateral medulla oblongata infarction BMJ Case Reports, October 11, 2009; 2009(oct11_1): bcr0220091625 - bcr0220091625. [Abstract] [Full Text]

				T. S. Moreira, A. C. Takakura, E. Colombari, and J. V. Menani Antihypertensive effects of central ablations in spontaneously hypertensive rats Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2009; 296(6): R1797 - R1806. [Abstract] [Full Text] [PDF]

				H. D. Schultz, Y. L. Li, and Y. Ding Arterial Chemoreceptors and Sympathetic Nerve Activity: Implications for Hypertension and Heart Failure Hypertension, July 1, 2007; 50(1): 6 - 13. [Full Text] [PDF]

				M. Nozoe, Y. Hirooka, Y. Koga, Y. Sagara, T. Kishi, J. F. Engelhardt, and K. Sunagawa Inhibition of Rac1-Derived Reactive Oxygen Species in Nucleus Tractus Solitarius Decreases Blood Pressure and Heart Rate in Stroke-Prone Spontaneously Hypertensive Rats Hypertension, July 1, 2007; 50(1): 62 - 68. [Abstract] [Full Text] [PDF]

				M. A. Sato, G. H. M. Schoorlemmer, J. V. Menani, O. U. Lopes, and E. Colombari Recovery of High Blood Pressure After Chronic Lesions of the Commissural NTS in SHR Hypertension, October 1, 2003; 42(4): 713 - 718. [Abstract] [Full Text] [PDF]

				M. A. Sato, E. Colombari, and S. F. Morrison Inhibition of neurons in commissural nucleus of solitary tract reduces sympathetic nerve activity in SHR Am J Physiol Heart Circ Physiol, May 1, 2002; 282(5): H1679 - H1684. [Abstract] [Full Text] [PDF]

				E. Colombari, M. A. Sato, S. L. Cravo, C. T. Bergamaschi, R. R. Campos Jr, and O. U. Lopes Role of the Medulla Oblongata in Hypertension Hypertension, September 1, 2001; 38(3): 549 - 554. [Abstract] [Full Text] [PDF]