In-vitro uptake and metabolism of [3H] corticosterone by mammary glands from pregnant, lactating, and post-lactational rats and by parametrial adipose tissue from lactating rats.
The study was designed to determine the influence of the physiological state on the in-vitro uptake and metabolism of glucocorticoid hormone by the mammary gland. [3H] Corticosterone was accordingly incubated with minced mammary glands from pregnant, lactating and post-lactational rats. The total uptake of [3H] corticosteroid was obtained from the concentration of radioactivity by the tissue and the specific activity of the steroid substrate. The extent of 21-acylation was determined as the percentage of the radioactivity in the chromatographed tissue extracts attributable to 21-acyl-[3H] corticosterone. The results indicated that the uptake of [3H] corticosteroid increased with advancing pregnancy, attained a high plateau level during lactation, and steadily declined during the post-lactational period. The extent of 21-acylation of [3H] corticosterone varied from 10 to 40%, fluctuating widely in all physiological states, particularly during the post-lactational period. It was inferred that the stromal elements, presumably the adipocytes, of the mammary gland can also acylate the corticosteroid hormone, a view which gained experimental support from similar studies with minced parametrial adipose tissue from lactating rats.
D000215:Acylation; D000273:Adipose Tissue / Q000378:metabolism; D000818:Animals; D002855:Chromatography, Thin Layer; D003345:Corticosterone / Q000378:metabolism*; D005260:Female; D007774:Lactation; D008321:Mammary Glands, Animal / Q000378:metabolism*; D011247:Pregnancy; D011270:Pregnancy, Animal; D051381:Rats; D011919:Rats, Inbred Strains; D014599:Uterus / Q000378:metabolism*
D003345:Corticosterone