Etofibrate suppresses neointima formation of the ballooned common carotid artery of rats.

The inhibition of neointima formation by drugs is a major goal to prevent restenosis following angioplasty. In the present study, the effect of etofibrate on blood lipids and vessels wall was investigated using a balloon injury rat model. Two weeks after ballooning the common carotid artery neointima formation was quantified by morphometric measurement of the neointimal area and cellularity in vessel cross sections, and by fluorometric evaluation of the DNA content. Etofibrate (160 mg/kg/day) had no effect on plasma triglyceride levels, but reduced serum cholesterol by about 25%. The injury-induced increase of both the neointimal area and the DNA-content was significantly inhibited by 47% (P < 0.005) and 34% (P < 0.05), respectively, in the drug-treated animals in comparison to the untreated control rats. The ratio of neointima and media was significantly (P < 0.001) reduced from 152.9 +/- 11.6% (controls) to 82.84 +/- 12.59% in the etofibrate-treated group. The cellularity (numerical profile and volume density of nuclei) in the neointima was similar in both groups. In conclusion, injury-induced neointima formation is reduced in etofibrate-treated animals, which could be due to an inhibition of smooth muscle cell proliferation.