Renin-Angiotensin System in Human Hypertension Due to Segmental Renal Ischemia

Dynamics of renin-angiotensin (RA) system under various conditions was studied in 8 hypertensive patients due to segmental renal ischemia. The ischemia in the kidney of these patients was localized lesion, involving only 10-30% of the affected kidney. Increased level of peripheral vein renin activity (PVRA) at basal condition was found in half of them. Irrespective of their resting PVRA, they responded to various renin secreting stimuli with more remarkable enhancement of PVRA than control group. Significantly higher renal vein renin activity was estimated on the affected side compared with that of the unaffected. Localized increase in renal renin content was proven in the ischemic area of the kidney. From these results, it may be concluded that RA system is etiologically related to the pathogenesis in this type of hypertension and that careful renin studies are practically useful to diagnose a small, but functionally significant, ischemic process in the kidney.