Expression of sodium pump activity and of transepithelial voltage induced by hormones in cultured cortical collecting tubule cells.
Primary monolayer cultures of polarized epithelia were derived from single cortical collecting tubules (CCT) of the mammalian kidney (rabbit). The expression of Na-K-ATPase activity (mol 10(-15)/min.cell) and of the transepithelial voltage (VT) in monolayers on membranes was measured in response to defined hormonal supplements of the nephron culture medium (NCM). Hormones were: triiodothyronine (T3; 10(-11) M), dexamethasone (10(-8) M), and aldosterone (10(-9) M). Control was NCM plus fetal calf serum (FCS; 3% v/v). Data are mean (SEM). Na-K-ATPase activity was 10.4 (6.2) in control (n = 27); 18.8 (5.2) in T3 (n = 35); 21.2 (5.5) in dexamethasone (n = 26), and 30.9 (6.5) in aldosterone (n = 24). VT (mV) was 4.2 (3.2) in control (n = 12); 12.7 (3.7) in T3 (n = 12); 16.8 (2.5) in dexamethasone (n = 12), and 28.4 (3.6) in aldosterone (n = 14). Data are evidence that thyroid and corticosteroid hormones selectively induce the postmitotic expression of the sodium carrier activity and other functions related to vectorial solute transport in this polarized epithelium.
Horster
M F
MF
Physiologisches Institut, Universität München, BRD.
Schmolke
M
M
Gleich
R
R
D000450:Aldosterone / Q000502:physiology; D000818:Animals; D001693:Biological Transport, Active; D002478:Cells, Cultured; D003907:Dexamethasone / Q000502:physiology; D004848:Epithelium / Q000378:metabolism; D006728:Hormones / Q000502:physiology*; D007672:Kidney Cortex / Q000378:metabolism*; D007684:Kidney Tubules / Q000378:metabolism*; D007685:Kidney Tubules, Collecting / Q000378:metabolism*; D008564:Membrane Potentials; D011817:Rabbits; D012964:Sodium / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D014284:Triiodothyronine / Q000502:physiology
D006728:Hormones; D014284:Triiodothyronine; D000450:Aldosterone; D003907:Dexamethasone; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase