Diabetes, Vol 39, Issue 12 1575-1579, Copyright © 1990 by American Diabetes Association
Nephropathy in model combining genetic hypertension with experimental diabetes. Enalapril versus hydralazine and metoprolol therapy
ME Cooper, TJ Allen, RC O'Brien, D Papazoglou, BE Clarke, G Jerums and AE Doyle
Department of Medicine, Austin Hospital, Heidelberg, Victoria, Australia.
We compared the effects of the angiotensin-converting enzyme inhibitor
enalapril and a conventional antihypertensive regimen (hydralazine and
metoprolol) on kidney function, albuminuria, and glomerular ultrastructure
in hypertensive diabetic and nondiabetic rats. Diabetes was induced with
streptozocin at 8 wk of age in spontaneously hypertensive (SHR) rats.
Antihypertensive drugs were administered in drinking water from the time of
induction of diabetes in all groups. Blood pressure reduction was equal in
the diabetic and nondiabetic SHR rats receiving either enalapril or
hydralazine plus metoprolol. In diabetic SHR rats, there was a rise in
serum creatinine after 32 wk, which did not occur in diabetic rats treated
with either antihypertensive regimen or in nondiabetic rats. Both drug
regimens reduced albuminuria in diabetic and nondiabetic SHR rats to a
similar degree. Enalapril and the combination of hydralazine and metoprolol
were associated with decreased glomerular basement membrane thickness and
glomerular volume in diabetic and nondiabetic SHR rats without significant
effect on fractional mesangial volume. Thus, antihypertensive therapy
retards the development of albuminuria, glomerular basement membrane
thickening, and glomerular hypertrophy in the rat in the presence or
absence of diabetes. No specific benefit of angiotensin-converting enzyme
inhibition was observed in these hypertensive models of nephropathy. Human
studies comparing the effects of different classes of antihypertensive
drugs on kidney function, proteinuria, and glomerular morphology are
warranted.