PREDICTIVE VALUE OF CAPTOPRIL TRANSIT RENOGRAPHY IN ESSENTIAL-HYPERTENSION AND DIABETIC NEPHROPATHY

Captopril renography was utilized to assess the presence of angiotensi n II dependent renovascular dysfunction in (1) 28 patients with mild t o moderate essential hypertension (EH) with unimpaired renal function, and (2) 25 hypertensive patients with diabetic nephropathy (HDN). The studies were classified according to the diagnostic criteria outlined by the Working Party on Diagnostic Criteria of Renovascular Hypertens ion with Captopril Renography and the mean parenchymal transit time (M PTT) was used as an index for detecting the presence of angiotensin II dependent renal haemodynamic change. Patients with EH showed non-sign ificant or non-specific alterations in the MPTT. Four patients in the HDN group showed a significant prolongation of MPTT in the presence of renin-angiotensin-aldosterone activation due to renal artery stenosis , and the other patients in this group showed a significant decrease i n MPTT after captopril, consistent with increased blood flow and impro ved tubular transport function in the presence of microangiopathy only . We conclude that addition of MPTT to the standard diagnostic criteri a of captopril renography may be helpful in predicting the beneficial or detrimental impact of angiotensin II inhibition treatment in HDN an d in limiting the test protocol in EH to one post-captopril study.