Effect of captopril on murine systemic lupus erythematosus disease.

The MRL/1 and New Zealand black-New Zealand white cross (NZB x W) mice spontaneously develop a disease similar to systemic lupus erythematosus in man. The effect of antihypertensive treatment on MRL/1 and NZB x W mice was studied with respect to survival, blood pressure, proteinuria, haematuria and renal histopathology. The treatment consisted of angiotensin converting enzyme (ACE) inhibitors (captopril and enalapril) and bretylium, a sympathetic blocker. Tail systolic blood pressure was measured with a strain gauge technique. All antihypertensive drugs caused a reduction in blood pressure in both strains. In MRL/1 bretylium and both ACE inhibitors improved renal histopathology, but only captopril prolonged survival, and it decreased proteinuria and haematuria. In NZB x W captopril decreased proteinuria but did not influence survival or renal histopathology. Bretylium was without any effect on these parameters. At the doses used captopril improves survival in MRL/1 mice and decreases proteinuria and haematuria in both MRL/1 and NZB x W mice. Since bretylium and enalapril lack this property despite a similar blood pressure reduction, it seems to be a drug-specific action.