Isradipine decreases the entry of radioiodine-labelled low-density lipoproteins into the arterial wall.

Experimental studies have demonstrated that isradipine significantly decreases the entry of radioiodine-labelled (125I) low-density lipoproteins (LDL) into the aorta. This study aimed to investigate whether similar effects could be detected in humans as well. Twelve patients (nine men and three women, aged from 35 to 53 years), all of whom had both hyperlipoproteinaemia (either type IIa or type IIb; mean total cholesterol: 296 +/- 25 mg/dl; mean LDL cholesterol: 208 +/- 22 mg/dl) and mild-to-moderate hypertension [mean systolic blood pressure (SBP): 149 +/- 12 mmHg; mean diastolic blood pressure (DBP): 104 +/- 4 mmHg] received isradipine (2 x 2.5 mg). Autologous radiolabelled (123I) LDL was reinjected and a gamma camera used to study the LDL kinetics before (at 20 min, 2 h and 20 h) and after (at the same time intervals) treatment with isradipine. Of interest were those arterial regions that are typically sites of atherosclerotic lesions (carotid artery, femoral artery). Results revealed three different types of LDL kinetics which were not altered by isradipine treatment. The quantitative LDL entry, however, was reduced by at least 4.7% with a maximum of 23.5% (p < 0.01). Only five vascular sites with type III kinetics were detected. These data suggest that isradipine may induce functional regression of atherosclerotic lesions.