SHORT-TERM TREATMENT WITH PROSTAGLANDIN E-1 ANALOG HAS LONG-TERM PREVENTIVE EFFECTS ON INTIMAL THICKENING IN BALLOON-INJURED RAT CAROTID ARTERIES

We examined effects of a prostaglandin E-1 analogue alprostadil on int imal thickening and arterial remodeling in balloon-injured rat carotid arteries. Right common carotid arteries were balloon-injured, and the ir left counterparts were sham-operated (uninjured). Rats were given a lprostadil (0.3 mu g/kg/min, continuous subcutaneous (s.c.) infusion) or vehicle for 1 week after the injury and sacrificed at 4 weeks or 8 weeks. Segments of common carotid arteries corresponding to balloon-in jured and uninjured sites were excised and subjected to elastica van G ieson staining. Cross-sectional areas were measured by computed planim etry. Alprostadil prevented intimal-thickening at both 4 and 8 weeks. In addition, alprostadil prevented the increase in intimal area/area s urrounded by external elastic lamina at both 4 and 8 weeks. Alprostadi l had no effects on body weight, heart rate, or systolic blood pressur e. Our study demonstrated that alprostadil administered only for the i nitial 1 week had long-term (up to 8 weeks) preventive effects on inti mal thickening. Alprostadil may be useful to prevent restenosis after balloon angioplasty.