Korean J Physiol Pharmacol.  1997 Dec;1(6):639-645.

Primary role of posterior hypothalamic cholinergic receptors in central regulation of blood pressure and heart rate in rats

• Kim SY
• Sung KW
• Koh HC
• Lee SB

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.

Keyword

Posterior hypothalamus; Cholinergic mechanism; Blood pressure; Heart rate; Muscarinic receptors; L-glutamate; Respiration; Spontaneous breathing; Rat

MeSH Terms

Animals
Atropine
Blood Pressure*
Carbachol
Glutamic Acid
Heart Rate*
Heart*
Hypothalamus, Posterior
Rats*
Receptors, Cholinergic*
Receptors, Muscarinic
Respiration
Atropine
Carbachol
Glutamic Acid
Receptors, Cholinergic
Receptors, Muscarinic