Determination of in vitro activity renin inhibitors by HPLC method.

A high-performance liquid chromatographic assay has been developed to the separation of angiotensin I, tetradecapeptide and the tetrapeptide Leu-Val-Tyr-Ser. This purpose is achieved in a single step, using HPLC technique in the reversed phase system. The method is based on enzymatic hydrolysis of a substrate renin (TDP) with formation of angiotensin I (DP). After 1 h incubation at 37 degrees C the reaction mixture is introduced directly into the chromatographic system. A 200 microl reaction mixture is needed for analysis. Acetonitrile gradient in 0.01 M ammonium acetate buffer allows a satisfactory separation of hydrolysis products. The application of this technique for the determination of in vitro renin activity and evaluation the potency of human renin inhibitors, employing the artificial renin substrate tetradecapeptide, is demonstrated.