Short-term treatment with prostaglandin E1 analogue has long-term preventive effects on intimal thickening in balloon-injured rat carotid arteries.

We examined effects of a prostaglandin E1 analogue alprostadil on intimal thickening and arterial remodeling in balloon-injured rat carotid arteries. Right common carotid arteries were balloon-injured, and their left counterparts were sham-operated (uninjured). Rats were given alprostadil (0.3 microgram/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-injured and uninjured sites were excised and subjected to elastica van Gieson staining. Cross-sectional areas were measured by computed planimetry. Alprostadil prevented intimal thickening at both 4 and 8 weeks. In addition, alprostadil prevented the increase in intimal area/area surrounded by external elastic lamina at both 4 and 8 weeks. Alprostadil had no effects on body weight, heart rate, or systolic blood pressure. Our study demonstrated that alprostadil administered only for the initial 1 week had long-term (up to 8 weeks) preventive effects on intimal thickening. Alprostadil may be useful to prevent restenosis after balloon angioplasty.