Pathophysiology in malignant hypertension: with special reference to the renin-angiotensin system

Pathophysiology of malignant hypertension, of which underlying disease was essential hypertension (EHT) in 33 cases and chronic glomerulonephritis (CGN) in 26 cases, was studied with reference to the renin-angiotensin system. Plasma renin activity (PRA) was significantly higher in the EHT than in the CGN group, and angiotensinII antagonist [Sar1, Ile8] angiotensin II (AIIA) induced a significant lowering of blood pressure only in the former group. PRA was linearly correlated with both pretreatment mean blood pressure (MBP, r=0.474, n=29, p< 0.01)and serum creatinine (r=0.540, n=29, p< 0.01) in the EHT group but not in CGN patients, although there was an inverse correlation between PRA and serum sodium in both groups. Multiple regression analysis revealed that PRA was independently related to MBP, serum creatinine, and serum sodium in the EHT group, but not in the CGN group. These results suggest that the renin-angiotensin system plays a significant role in elevating blood pressure and deteriorating renal function in malignant hypertension derived from EHT, but it is less important in CGN related hypertension.