Effect of muscarine on release of catecholamines from the perfused adrenal gland of the cat.
1 The secretory effect of muscarine was studied in the perfused adrenal gland of the cat. During perfusion of the adrenal gland with Krebs-bicarbonate solution containing muscarine 480 microM, the rate of catecholamine (CA) secretion was 2.02 +/- 0.43 micrograms/2 min in the first 2 min; thereafter, CA output declined only moderately, to reach about 70% of the initial value after 10 min. Secretory responses to brief infusions of muscarine remained reproducible for at least the first 3 infusions. 2 When the adrenal gland was perfused with muscarine (480 microM), infusions of high K+, nicotine, or veratridine produced their usual responses. A 100 fold lower dose of muscarine also failed to modify these responses. 3 During perfusion with high K+, muscarine evoked a secretory response that was only slightly smaller than the response to muscarine alone. 4 It is concluded that muscarine and nicotine activate CA secretion in the cat adrenal gland by independent mechanisms and that the muscarinic response, unlike the nicotinic response, is not readily desensitized.
D000311:Adrenal Glands / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002395:Catecholamines / Q000378:metabolism*; D002415:Cats; D066298:In Vitro Techniques; D009116:Muscarine / Q000494:pharmacology*; D009538:Nicotine / Q000494:pharmacology; D010477:Perfusion; D011188:Potassium / Q000494:pharmacology; D014701:Veratridine / Q000494:pharmacology
D002395:Catecholamines; D009538:Nicotine; D014701:Veratridine; D009116:Muscarine; D011188:Potassium; D002118:Calcium