Suppression of aortic atherosclerosis in cholesterol-fed rabbits by purified rabbit interferon.

Abstract
The effectiveness of rabbit interferon in suppressing atherosclerosis was evaluated in rabbits fed a diet containing 1% cholesterol. Ten male New Zealand White rabbits received intramuscular injections of 1 million units of interferon twice a week, while a control group of 10 rabbits received injections of buffer. Both groups had average serum cholesterol levels of over 2000 mg/dl during the 8-week experimental period. Interferon treatment resulted in no significant hypolipidemic effect or changes in lipoprotein composition. Atherosclerotic lesions in aortas were quantified both macroscopically and microscopically. Interferon treatment decreased the grossly visible lesion area significantly from 25 +/- 4% to 8 +/- 1% (mean +/- SEM, p less than 0.005) compared to the untreated group. Microscopic analysis of serial cross-sections of aortic segments revealed significant (p less than 0.01) reductions in both lesion size and frequency in the interferon-treated group. Electron microscopy also showed that interf...