title: Response of adrenal 3beta-hydroxy-delta5-steroid dehydrogenase to adrenocorticotropin treatment in thiouracil-fed male mice.
abstract: A number of parallels can be drawn between the reported endocrine status of thiouracil-fed young rodents and that of aged animals, particularly with regard to the hypothalamus-pituitary-adrenal axis. Since the activity of the adrenal steroidogenic enzyme 3beta-hydroxy-delta5-steroid dehydrogenase (3beta-HSD) has been shown to be depressed in aged rats and mice, the present study was done to determine whether exposure of young mice to thiouracil had a similar effect on adrenal 3beta-HSD activity. Feeding the goitrogen thiouracil at 0.25% (w/w) of the maternal diet from conception, and keeping it 0.25% of the offsprings' diet after weaning, significantly elevated activity of 3beta-HSD per gram of adrenal gland above control levels in 4-month-old mice, perhaps to compensate for depressed adrenal mass. Daily subcutaneous injections of physiological saline (0.9%) for 4 days was sufficient to increase 3beta-HSD activity per gram of adrenal tissue in euthyroid (P less than 0.05) but not in thiouracil-fed mice. Subcutaneous administration of ACTH (2 IU daily for 4 days) significantly increased adrenal 3beta-HSD activity to comparable levels in thiouracil-fed and euthyroid animals. Thus, thiouracil enhances the activity of 3beta-HSD per gram of adrenal tissue and does not prevent response of enzyme activity to exogenous ACTH.
mesh_terms: D015096:3-Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D000311:Adrenal Glands / Q000033:anatomy & histology / Q000201:enzymology; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000375:Aging; D000818:Animals; D001835:Body Weight; D004032:Diet; D008297:Male; D051379:Mice; D009929:Organ Size; D013889:Thiouracil / Q000008:administration & dosage*
chemical_list: D013889:Thiouracil; D000324:Adrenocorticotropic Hormone; D015096:3-Hydroxysteroid Dehydrogenases