Chronic Pressor Effect of Kidney Extracts Containing Renin in Experimental Hypertensions

A course of daily intramuscular injections of dog renin produced a maintained chronic pressor effect persisting for months during and following the renin injections in a majority of renal hypertensive dogs. Semipurified hog renin produced a temporary chronic pressor effect persisting for several weeks or somewhat longer but not throughout the renin injections in a minority of renal hypertensive dogs. The maintained chronic pressor effect was obtained only in the absence of antirenin; the temporary chronic pressor effect was lost when antirenin appeared in the plasma. Normotensive dogs were significantly less responsive to the chronic pressor effect of dog and hog renins than were renal hypertensive dogs. The mechanism of the chronic pressor effects is unknown.