id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-007084-4niom5mw	POPPLEWELL, PHILIP Y.	The Influence of Age on Steroidogenic Enzyme Activities of the Rat Adrenal Gland: Enhanced Expression of Cholesterol Side-Chain Cleavage Activity(*)	1987-06-01		.txt	text/plain	5237	325	44	Cholesterol side-chain cleavage enzyme activity, the rate-limiting enzyme in corticosterone biosynthesis, was measured in adrenal mitochondria isolated from 2-, 12-, and 18-month-old male Sprague-Dawley rats. Under basal conditions (without 25-hydroxycholesterol), cholesterol side-chain cleavage activity (expressed as nanomoles of pregnenolone produced per min mg protein" 1 ) increased (P < 0.001) from a mean (±SE) of 0.43 ± 0.06 in 2-month-old rats to 1.26 ± 0.11 and 1.51 ± 0.06 in the 12-and 18-month-old rats, respectively. Accordingly, we measured cholesterol side-chain cleavage, 3/3-HSD, 21-hydroxylase, 11/3-hydroxylase activities, and cytochrome P450 contents in appropriate mitochondrial and microsomal fractions of adrenals from 2-, 12-, and 18-month-old rats. Results of the present study also suggest that the decline in steroidogenesis observed in adrenocortical cells isolated from senescent rats is not related to a reduction in cholesterol side-chain cleavage activity or other steroidogenic responses, as measured in vitro in isolated subcellular components.	./cache/cord-007084-4niom5mw.txt	./txt/cord-007084-4niom5mw.txt