The effect of interferon on mouse myocardial capillaries: an ultrastructural study.

Abstract

Cardiotoxicity, including ischemia and myocardial infarction, is one of the complications observed after treatment with interferon (IFN). Therefore, the question has been raised whether IFN may cause damage to the small myocardial blood vessels. In this study, 400 U of IFN-alpha-2b per g of body weight were injected intraperitoneally into 2 groups of C57 B1 mice, 5 days a week for 3 and 5 months, respectively. Thin sections of the myocardium were examined with a transmission electron microscope and the ultrastructure of the capillaries was compared with that of control animals. The results showed a statistically significant increase in the thickness of the endothelial processes of the myocardial capillary walls in the mice treated with IFN, with a subsequent decrease in the size of the capillary lumen. The entire capillary area was not affected. These findings may serve as an additional explanation for the cardiac complications observed in patients treated with IFN.