The use of 99Tcm-EC for captopril test in patients with hypertension.

The purpose of this study was to evaluate the new renal radiopharmaceutical 99Tcm-N,N-ethylene-L-dicysteine (99Tcm-EC) in patients with hypertension, applying the captopril test. Twelve controls, 45 patients with essential hypertension (EH) and 8 with renovascular hypertension (RVH) were investigated. The captopril test was assessed using different parameters of kidney function. In the controls they were: Tmax 3.33 min, T1/2 9.27 min, retention index 0.30. In the patients with EH they were: before captopril Tmax 4.87 min, T1/2 16.35 min, retention index 0.41; after captopril Tmax 4.19 min, T1/2 13.78 min, retention index 0.40. In the patients with RVH they were: before captopril Tmax 6.50 min, T1/2 not reached, retention index 0.70; after captopril Tmax 9.33 min, T1/2 not reached, retention index 0.90. Our results indicate that this new renal radiopharmaceutical can be reliably used for carrying out the captopril test in patients with hypertension, in order to screen those with RVH.