ULTRASTRUCTURE OF ATHEROMATOUS LESIONS EXPERIMENTALLY-INDUCED IN SYRIAN-HAMSTERS OF THE APA STRAIN

In order to examine whether diabetes enhances primary aortic lesions u p to atherosclerotic ones, mild primary lesions were induced in aorta of APA hamsters by an administration of vitamin D-2 (VD) and/or stop-a nd-reflow (SR)-operation, a modification of renal artery clamping. At 2 months after the treatment with the combination of VD-administration and SR-operation, atheromatous lesions, characterized by an appearanc e of many foam cells in the intima, were observed in the abdominal aor ta, the site of SR-operation, in streptozotocin (SZ)-induced diabetic APA hamsters. Foam cells in the atheromatous lesions were originated f rom smooth muscle cells and monocyte/macrophages. On the other hand, n either VD-administration alone nor SR-operation alone developed athero matous lesions in SZ-induced diabetic APA hamsters. In conclusion, we succeeded in a rapid induction of atherosclerotic lesions in abdominal aorta of SZ-induced diabetic APA hamsters by the combination of VD-ad ministration and SR-operation.