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Pathophysiology in malignant hypertension: with special reference to the renin-angiotensin system
Insights
Malignant hypertension from essential hypertension involves the renin-angiotensin system, impacting blood pressure and kidney function. This system is less critical in malignant hypertension secondary to chronic glomerulonephritis.
Area of Science:
- Nephrology
- Cardiovascular Medicine
- Endocrinology
Background:
- Malignant hypertension is a severe form of hypertension with significant morbidity and mortality.
- Understanding the underlying pathophysiology is crucial for effective treatment.
- The renin-angiotensin system is implicated in blood pressure regulation and kidney disease.
Purpose of the Study:
- To investigate the role of the renin-angiotensin system in the pathophysiology of malignant hypertension.
- To compare the renin-angiotensin system's involvement in malignant hypertension secondary to essential hypertension versus chronic glomerulonephritis.
Main Methods:
- Studied 59 patients with malignant hypertension (33 essential hypertension, 26 chronic glomerulonephritis).
- Measured plasma renin activity (PRA).
- Administered angiotensin II antagonist [Sar1, Ile8]angiotensin II (AIIA) to assess blood pressure response.
- Correlated PRA with mean blood pressure, serum creatinine, and serum sodium.
Main Results:
- Plasma renin activity (PRA) was significantly higher in essential hypertension (EHT) than chronic glomerulonephritis (CGN) groups.
- Angiotensin II antagonist lowered blood pressure only in the EHT group.
- In EHT, PRA correlated with mean blood pressure, serum creatinine, and serum sodium.
- These correlations were not observed in the CGN group.
Conclusions:
- The renin-angiotensin system plays a significant role in elevating blood pressure and worsening renal function in malignant hypertension originating from essential hypertension.
- The renin-angiotensin system is less critical in the pathophysiology of malignant hypertension associated with chronic glomerulonephritis.
Abstract:
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 angiotensin II 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 less than 0.01) and serum creatinine (r = 0.540, n = 29, p less than 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.