Circulating life of renin and the sustained pressor principle in normal, nephrectomized and ischemic kidney rats

The role of the kidney in the sustained pressor effect of the sustained pressor principle (SPP) was investigated. It was found that the half life of SPP in the circulating blood of nephrectomized rats and rats with a single ischemic kidney was longer than that of renin. In intact DOCA treated rats, the half lives of renin and SPP were similar. The normal kidney appears to produce a factor which modifies the SPP molecule leading to a reduction of its half life. This factor may convert SPP to renin, since previous experiments have indicated that renin and SPP are closely related.