In the present study we report on a direct effect of prostaglandin E2 (PGE2) on ouabain binding and Na-K-adenosinetriphosphatase (Na-K-ATPase) activity in a clone of Madin-Darby canine kidney cells, a renal cell line with collecting duct properties. Incubation of the cells with low concentrations (pM) of PGE2 produced a concomitant reduction of ~50% in the activity of Na-K-ATPase in the cell homogenate and in ouabain binding to the intact cells (half-maximal inhibition of ~0.1 pM). The inhibition was apparent within 10 min of preincubation of the cells with PGE2. Scatchard analysis of the binding demonstrated that the treatment with PGE2 reduced the number of ouabain binding sites without a change in the dissociation constant. PGE1 and PGF(2α) (10 nM) did not affect ouabain binding or Na-K- ATPase activity. The fast, potent, and specific effect of PGE2 suggests that the diuretic/natriuretic effect of prostaglandins of the E series in the collecting tubule, in addition to the interference with the activity of arginine vasopressin, may result from a direct reduction in the number of the Na-K-ATPase active units, via a prostaglandin receptor.
|Journal||American Journal of Physiology - Renal Fluid and Electrolyte Physiology|
|Issue number||1 33-1|
|State||Published - 1 Jan 1993|
- cultured renal cells
- fast regulation
- sodium pump