Phosphate accumulation by the isolated renal tubule and the effects of parathyroid hormone and cyclic adenosine monophosphate.

The effects of metabolic and transport inhibitors and PTH, cAMP, db-cAMP, and theophylline on Pi uptake by an isolated rat renal tubular preparation has been investigated. Pi uptake by this preparation was a saturable process, was O2- and sodium-dependent, was inactivated by heat=treatment, and was inhibited by dinitrophenol. iodacetate, ouabain, and a decrease in temperature from 37 degrees to 4 degrees C. PTH and cAMP stimulated Pi uptake by energy-dependent and ouabain-inhibitable mechanisms.