The aim of the study was to evaluate the effect of
angiotensin converting enzyme inhibition on renoscintigraphic curves using
DTPA as a tracer in patients with essential (EH) and renovascular (RVH)
hypertension. Twenty four patients with EH and sixteen with RVH were studied. Protocol consisted of control renoscintigraphy with
DTPA and the second one after
captopril administration in dose 25 mg performed after three days. Relative
DTPA uptake of the
single kidney was calculated from the curve time-activity between 120 and 180 second after tracer administration. Results were expressed as a quotient of the relative
DTPA uptake of ischemic or "weaker" kidney to the
DTPA uptake of both kidneys (coefficient A) or contralateral one (coefficient B). Coefficient A in basic renoscintigraphy did not differ in patients with EH and RVH and was 45.81 +/- 3.02% and 44.66 +/- 6.17% respectively. In renoscintigraphy with
captopril coefficient A decreased significantly (P < 0.001) in patients with RVH and was significantly lower (p < 0.05) than in patients with EH. Change (delta) of coefficient B after
captopril was significantly higher in patients with RVH (p < 0.001). Significant correlations were found between delta coefficient A and delta diastolic (DAP) and mean (MAP) arterial pressure as well as delta plasma
renin activity (PRA) after
captopril in patients with RVH. Similarly, relationships were shown between percentage change (% delta) of coefficient B and % delta of systolic (SAP), DAP and MAP as well as delta PRA after
captopril in patients with RVH.