EFFECT OF GLUTAURINE ON PLASMA-RENIN ACTIVITY IN THE RAT AND THE DOG

Glutaurine (γ-l-glutamyl-taurine), a bioactive substance isolated from bovine parathyroid and reproduced synthetically, a putative hormone, increased the plasma renin concentration (PRC) and plasma renin activity (PRA) in the rat and the dog. In both species peak values were observed 30 min after intravenous injection of 1 μg/kg glutaurine. The effect showed a dose-dependent optimum. Intravenous administration of lower glutaurine doses (1 μg/kg) produced a statistically significant decrease of blood pressure in dogs 15 min following injection. Administration of a 10 μg/kg dose significantly reduced effective renal plasma flow (CPAH) from the 15th minute on. Plasma renin activity (PRA) was significantly enhanced already in the 15th minute after injection and reached a maximum in the 30th minute with all dose levels applied. Pretreatment with vitamin A (10,000 IU/kg/day im for 6 days) had practically no influence on the glutaurine-produced changes of the above parameters. The described effects of glutaurine are supposed to be intrarenal or are based on action on the renal cortex. According to our hypothesis glutaurine, as a lysosome labilizing substance, acts on the juxtaglomerular cell granules considered to be lysosome analogs. © 1979.