Vasopressin rapidly stimulates Na entry and Na-K pump activity in quiescent cultures of mouse 3T3 cells.
Addition of (Arg) vasopressin to quiescent cultures of Swiss 3T3 cells rapidly stimulates an ouabain-sensitive 86Rb uptake. In contrast the hormone has no significant effect on the rate of efflux of this cation from preloaded cells. The stimulation of 86Rb uptake is cycloheximide-insensitive, occurs within minutes of hormone addition and results from an increase in the Vmax of the uptake system. Vasopressin stimulates ion uptake in a concentration-dependent fashion (1--100 ng/ml); oxytocin also stimulated the Na-K pump but at significantly higher concentrations. The stimulation of the Na-K pump by vasopressin is apparently mediated by an increase in Na entry into the cells, since the hormone 1) strikingly shifts the concentration dependence on Na+ of the Na-K pump, 2) increases 22Na uptake, and 3) increases intracellular Na contents when the efflux of this ion is blocked by ouabain. Since vasopressin is a potent mitogen for Swiss 3T3 cells, the results provide further evidence in support of a possible role of monovalent ion fluxes in signalling the initiation of growth stimulation.
D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology*; D001693:Biological Transport, Active / Q000187:drug effects; D001769:Blood; D002460:Cell Line; D007399:Interphase; D051379:Mice; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism*; D012413:Rubidium / Q000494:pharmacology; D012964:Sodium / Q000378:metabolism*
D001127:Arginine Vasopressin; D010042:Ouabain; D012964:Sodium; D012413:Rubidium; D011188:Potassium