Hormonal induction of Na-K-ATPase in developing proximal tubular cells.
The outer 150-micrometers layer of the renal cortex of the rat consists mainly of proximal tubules (PT). In this layer Na-K-ATPase (mumol Pi . mg protein-1 . h-1) increases from 3.45 +/- 0.19 (SE) in 10-day-old rats (R10) to 5.90 +/- 0.28 in 20-day-old rats (R20) to 9.52 +/- 0.42 in 40-day-old rats (R40). Betamethasone in pharmacologic doses increases Na-K-ATPase in R10, R20, and R40 to 11.5 +/- 1.19, 13.4 +/- 0.64, and 13.3 +/- 0.60, respectively. Estrogen in pharmacologic doses increases Na-K-ATPase to 9.1 +/- 0.46 in R20 and decreases Na-K-ATPase to 7.6 +/- 0.39 in R40. Aldosterone in a dose of 10 micrograms/100 g BW increases Na-K-ATPase to 8.7 +/- 0.26 in R20; in a dose of 40 micrograms/100 g BW it increases Na-K-ATPase to 6.9 +/- 0.35 in R10. However, aldosterone in a dose of 80 micrograms/100 g BW is needed to cause an increase in R40 to 13.4 +/- 0.37. Treatment with canrenone from the 10th to the 20th day increases Na-K-ATPase. It is concluded that the immature PT cells are particularly sensitive to hormone induction of Na-K-ATPase and that the sensitivity is maximal during fairly late stages of cellular differentiation. Moreover, the inductive effect is probably mediated via glucocorticoid receptors.
D000375:Aging; D000450:Aldosterone / Q000494:pharmacology*; D000818:Animals; D001623:Betamethasone / Q000494:pharmacology; D002192:Canrenone / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004790:Enzyme Induction; D004967:Estrogens / Q000494:pharmacology; D007687:Kidney Tubules, Proximal / Q000201:enzymology*; D008297:Male; D051381:Rats; D011965:Receptors, Glucocorticoid / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000096:biosynthesis* / Q000378:metabolism
D004967:Estrogens; D011965:Receptors, Glucocorticoid; D000450:Aldosterone; D002192:Canrenone; D001623:Betamethasone; D000254:Sodium-Potassium-Exchanging ATPase