The effect of etorphine on nicotine- and muscarine-induced catecholamine secretion from perfused rat adrenal glands.
The effect of etorphine on nicotine and muscarine-mediated catecholamine (CA) release from isolated perfused rat adrenal glands was investigated. Nicotine increased CA secretion at the low concentration of 0.5 micrograms while higher concentrations of muscarine (5 micrograms) were required. Moreover, muscarine released primarily epinephrine (EP) from rat adrenal glands while nicotine released norepinephrine (NE) and Ep. Etorphine inhibited NE and EP release evoked by nicotine to the same extent, whereas, muscarine-mediated release of NE and EP was not affected. Mecamylamine and verapamil inhibited nicotine but not muscarine-induced CA secretion. Our results suggest that etorphine preferentially interacts with nicotinic receptors on rat adrenal chromaffin cell membranes.
Chen
Y M
YM
Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence 66045.
Dixon
W R
WR
D000109:Acetylcholine / Q000494:pharmacology; D000311:Adrenal Glands / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D004837:Epinephrine / Q000378:metabolism*; D005048:Etorphine / Q000494:pharmacology*; D008297:Male; D008464:Mecamylamine / Q000494:pharmacology; D009019:Morphinans / Q000494:pharmacology*; D009116:Muscarine / Q000494:pharmacology*; D009538:Nicotine / Q000494:pharmacology*; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011976:Receptors, Muscarinic / Q000378:metabolism; D011978:Receptors, Nicotinic / Q000378:metabolism; D014700:Verapamil / Q000494:pharmacology
D009019:Morphinans; D011976:Receptors, Muscarinic; D011978:Receptors, Nicotinic; D005048:Etorphine; D008464:Mecamylamine; D009538:Nicotine; D009116:Muscarine; D014700:Verapamil; D000109:Acetylcholine; D009638:Norepinephrine; D004837:Epinephrine