Effects of antibody to renal plasma membrane on urinary excretion of adenosine 3',5'-monophosphate and phosphate induced by parathyroid hormone infusion in rats

Studies were made on the effects of pretreatment of rats with antibody to renal cortical plasma membrane (anti-RPM) on the urinary excretion of cAMP and phosphate induced by infusion of parathyroid hormone (PTH). With PTH infusion, the increase in the urinary excretion of cAMP and phosphate were not parallel. Infusion of 1-40 mg anti-RPM inhibited PTH-induced increase in urinary phosphate excretion but not the increase in urinary cAMP. Infusion of 100 mg of anti-RPM inhibited PTH-induced increases in the excretion of both substances. Infusion of nonimmunized rabbit immunoglobulin (IgG; normal IgG) did not affect PTH-induced increases in the excretion of either cAMP or phosphate. In vitro in isolated renal tubules, with 10 mg/ml anti-RPM, the increases in cAMP content induced by PTH were significantly less than those seen with lower concentrations of this antibody or with normal IgG.