Primary role of posterior hypothalamic cholinergic receptors in central regulation of blood pressure and heart rate in rats.
- Author:
Seong Yun KIM
1
;
Ki Wug SUNG
;
Hyun Chul KOH
;
Sang Bok LEE
Author Information
1. Department of Pharmacology, Catholic University Medical College, Seoul 137-701, South Korea.
- Publication Type:Original Article
- Keywords:
Posterior hypothalamus;
Cholinergic mechanism;
Blood pressure;
Heart rate;
Muscarinic receptors;
L-glutamate;
Respiration;
Spontaneous breathing;
Rat
- MeSH:
Animals;
Atropine;
Blood Pressure*;
Carbachol;
Glutamic Acid;
Heart Rate*;
Heart*;
Hypothalamus, Posterior;
Rats*;
Receptors, Cholinergic*;
Receptors, Muscarinic;
Respiration
- From:The Korean Journal of Physiology and Pharmacology
1997;1(6):639-645
- CountryRepublic of Korea
- Language:English
-
Abstract:
The purpose of the present study is to determine the role of muscarinic cholinergic receptors of posterior hypothalamus in the central blood pressure regulation when respiration is controlled. In anesthetized and artificially ventilated rats, vasodepressor response was evoked by injection of L-glutamate (10 nmol) neuroexcitatory amino acid into the posterior hypothalamic area. The injection of carbachol (0.5 ~ 8 nmol) into the same area induced dose-dependent vasodepressor and bradycardic responses. Pretreatment with atropine (4 nmol) completely blocked the vasodepressor response to carbachol (2 nmol). In contrast, in spontaneously breathing rats, the injection of carbachol (8 nmol) into the posterior hypothalamic area induced the vasopressor and tachycardic responses. These results suyggest that the muscarinic cholinergic receptors in the posterior hypothalamic area primarily play an inhibitory role in the central regulation of blood pressure and heart rate.
