Lovastatin, a HMG-CoA reductase inhibitor, is known to show antiproliferative effects on VSMC after vessel injury, but a large amount of the drug is needed orally for this purpose. This study investigated the effects of lovastatin given locally to injured carotid arteries of rats on reducing neointimal hyperplasia.

Lovastatin was given perivascularly to balloon-injured carotid arteries of 21 rats in 1 microM to the low-dose group, and 30 microM to the high-dose group. The control group was treated with pluronic gel only. Two weeks later, the lumen area, neointimal areas and the number of actively proliferating cells were obtained and compared.

Neointimal area was 0.113±0.032 mm², 0.065±0.017 mm², 0.072±0.017 mm² in the control, low-dose and high-dose groups respectively. The area was significantly smaller in the treatment groups (p<0.05), but no significant difference was observed between the treatment groups. The number of actively proliferating cells per mm² of neointimal area were 714.5±227.4, 688.4±333.7, and 1526.3±744.0 in the groups respectively, and the number was significantly high in the high-dose group (p<0.05).

Local administration of lovastatin is effective in reducing neointimal hyperplasia after vascular injury, but extremely high doses are not needed locally for this purpose.