Fumiaki Suzuki

High molecular weight renin in stroke-prone spontaneously hypertensive rats

Abstract The major form of renin in the plasma of the malignant phase of the strokeprone spontaneously hypertensive rat was a high molecular weight renin (M r = 56 000 ± 2000 , major isoelectric point ( p I) = 5.70 ± 0.08 ) instead of normal circulating renin of low molecular weight form. A high molecular weight renin (M r = 52 000 ± 3600 and p I = 5.60 ± 0.07 ) was also detected in kidney extracts of stroke-prone spontaneously hypertensive rats and control Wistar Kyoto strain of rats during all stages of their lives. However, there was no difference in the molecular weight and in the pI value of high molecular weight renin in the kidney extract between Wistar Kyoto rats and stroke-prone spontaneously hypertensive rats. Molecular properties of high molecular weight renin in the kidney extracts were very similar to those of high molecular weight renin in the plasma of the malignant phase of stroke-prone spontaneously hypertensive rats. Besides high molecular weight renin, a low molecular weight renin (M r = 35 600 ± 2900 and major p I value = 5.15 ± 0.05 ) was also observed in kidney extracts of Wistar Kyoto rats and stroke-prone spontaneously hypertensive rats during all stages of their lives, and its molecular properties were similar to those in their plasma. Therefore, a clear molecular shift of renin was observed in the plasma of the malignant phase of stroke-prone spontaneously hypertensive rats, but not in their kidney extracts.