Studies on the Interactions of M1-, M2- Receptors with Nicotinic Receptors in Rabbit Sympathetic Ganglia.
- Author:
Chun Sik RYU
1
;
Sam Suk KANG
;
Je Hyuk LEE
;
Jong Keun KIM
Author Information
1. Department of Neurosurgery, Chonnam University Medical School, Kwangju, Korea.
- Publication Type:Original Article
- Keywords:
Experiment;
Sympathetic ganglia;
Muscarinic;
Nicotinic receptor antagonist;
Agonist
- MeSH:
(4-(m-Chlorophenylcarbamoyloxy)-2-butynyl)trimethylammonium Chloride;
Blood Pressure;
Bradycardia;
Dimethylphenylpiperazinium Iodide;
Electric Stimulation;
Ganglia, Sympathetic*;
Ganglion Cysts;
Mecamylamine;
Pirenzepine;
Rabbits;
Receptors, Nicotinic*
- From:Journal of Korean Neurosurgical Society
1994;23(11):1234-1243
- CountryRepublic of Korea
- Language:English
-
Abstract:
Effects of a M1 receptor antagonist, pirenzepine, a M2 receptor antagonist, AF-DX116, and a nicotinic receptor antagonist, mecamylamine on the pressor responses to preganglionic sympathetic nerve stimulation(PNS) and McN-A-343 and DMPP in spinal(pithed) rabbits were investigated in order to elucidate a functional role of M1, M2 and nicotinic receptors in ganglionic transmission. Pirenzepine and AF-DX116 selectively inhibited the McN-A-343-induced pressor reponse in chlorisondamine-treated rabbit and the BCh-induced bradycardia, respectively. Electrical stimulations of preganglionic sympathetic outflow at T8 level produced increases in blood pressure. Pirenzepine(3 microgram/kg) significantly inhibited the PNS-induced pressor response and the degree of inhibition was not changed by increasing the doses to 100 microgram/kg. AF-DX116(100 microgram/kg) had no effect on the PNS-induced pressor response. Mecamylamine inhibited the PNS-induced pressor response in a dose-dependent manner. The inhibitory action of mecamylamine was significantly augmented by combined-treatment with pirenzepine(30 microgram/kg) but AF-DX116(100 microgram/kg) did not affect the inhibitory action of mecamylamine. McN-A-343 and DMPP elicited pressor response in the spinal rabbit. Pirenzepine and AF-DX116 dose-dependently inhibited the McN-A-343-induced pressor response but they did not affect DMPP-induced pressor response. Mecamylamine inhibited both pressor responses induced by Mc-N-343- and DMPP. These results suggest that not only nicotinic receptors but also M1 receptors play a facilitatory role in ganglionic transmission but M2 receptors do not contribute the transmission in spinal(pithed) rabbits.
