Effects of chronic nicotine administration on the denervated rat adrenal medulla.
1 The effects of chronic nicotine administration (1 or 10 mg/kg, s.c., twice daily) were studied in intact and denervated rat adrenal glands to determine the relative roles of central input and direct actions on catecholamines. 2 Catecholamine depletion was obtained in the intact glands from 1-7 days of treatment with 10 mg/kg, with recovery by 14 days of treatment; catecholamines were not decreased in denervated adrenal glands. 3 Catecholamine depletion was accompanied by a decline in functional storage vesicles (determined by [3H]-adrenaline uptake per gland) in the intact side, while no change was seen in the denervated side; the proportion of newly synthesized vesicles increased markedly during 1-7 days of treatment with 10 mg/kg in the intact side, while a much smaller increase of shorter duration was seen in the denervated adrenal gland. 4 Chronic nicotine administration at either dose level induced tyrosine hydroxylase in both intact and denervated glands, but the increase occurred more slowly in the denervated glands. 5 Dopamine beta-hydroxylase levels increased similarly in both sides during treatment with nicotine (10 mg/kg). 6 These studies suggest that although long-term adrenal denervation eliminates the catecholamine depletion caused by chronic administration of nicotine, the mechanisms for induction of catecholamine synthesizing enzymes are still capable of responding to the drug.
D000313:Adrenal Medulla / Q000187:drug effects* / Q000201:enzymology / Q000294:innervation / Q000378:metabolism; D000818:Animals; D002395:Catecholamines / Q000378:metabolism; D002714:Chlorisondamine / Q000494:pharmacology; D004299:Dopamine beta-Hydroxylase / Q000378:metabolism; D004837:Epinephrine / Q000378:metabolism; D007490:Iproniazid / Q000494:pharmacology; D008297:Male; D009538:Nicotine / Q000494:pharmacology*; D051381:Rats; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
D002395:Catecholamines; D009538:Nicotine; D007490:Iproniazid; D014446:Tyrosine 3-Monooxygenase; D004299:Dopamine beta-Hydroxylase; D002714:Chlorisondamine; D004837:Epinephrine