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International Journal of Hypertension
Volume 2014, Article ID 723939, 6 pages
Research Article

Participation of 5-HT and AT1 Receptors within the Rostral Ventrolateral Medulla in the Maintenance of Hypertension in the Goldblatt 1 Kidney-1 Clip Model

1Federal University of São Paulo, School of Medicine, Rua Botucatu 862, 04023-060 São Paulo, SP, Brazil
2Federal University of Espirito Santo, 29042-751 Vitória, ES, Brazil
3UNIVIX Medical School, 29075-080 Vitória, ES, Brazil
4UNESC Medical School, 29703-900 Colatina, ES, Brazil
5EMESCAM Medical School, 29045-402 Vitória, ES, Brazil

Received 30 April 2013; Accepted 2 December 2013; Published 21 January 2014

Academic Editor: Claudio Borghi

Copyright © 2014 Cássia T. Bergamaschi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The hypothesis that changes in neurotransmission within the rostral ventrolateral medulla (RVLM) are important to maintain the high blood pressure (BP) was tested in Goldblatt one kidney-one clip hypertension model (1K-1C). Male Wistar rats were anesthetized (urethane 1.2 g/kg, i.v.), and the effects of bilateral microinjections into the RVLM of the following drugs were measured in 1K-1C or control groups: glutamate (0.1 mol/L, 100 nL) and its antagonist kynurenic acid (0.02 mol/L, 100 nL), the angiotensin AT1 receptor antagonist candesartan (0.01 mol/L, 100 nL), and the nonselective 5-HT receptor antagonist methiothepin (0.06 mol/L, 100 nL). Experiments in 1K-1C rats were performed 6 weeks after surgery. In anesthetized rats glutamate response was larger in hypertensive than in normotensive rats (H: ; N:  mmHg). In contrast, kynurenic acid microinjection into the RVLM did not cause any change in BP in either group. The blockade of either AT1 or 5-HT receptors within the RVLM decreased BP only in 1K-1C rats. A largest depressor response was caused by 5-HT receptor blockade. The data suggest that 5-HT and AT1 receptors act tonically to drive RVLM in 1K-1C rats, and these actions within RVLM contribute to the pathogenesis of this model of hypertension.