Ultrastructure of arteries in rats fed a high-fat cholesterol diet. Intimal thickening of a small muscular artery.
Focal nodular intimal thickening developed in a small muscular artery (tarsal pedis) of rats fed a diet containing 28% neutral fat and 2% cholesterol for three months. Examination by electron microscopy showed the main cellular component of these intimal lesions to be a smooth muscle cell. Single unidentified cells were present in the subendothelial region. The internal elastic membrane was fragmented and a few smooth muscle cells were seen between the fragments, extending from the media into the intima. Numerous vesicles were present in the intercellular space, a cluster being enclosed within a basement membrane in places. No lipid accumulation was found. The findings point to an important role for smooth muscle cells in the initiation of atherosclerosis, and suggest that lipid accumulation is a secondary event in the development of this process in muscular arteries in this animal model.
D000818:Animals; D001158:Arteries / Q000648:ultrastructure*; D002784:Cholesterol / Q000097:blood; D002791:Cholesterol, Dietary / Q000008:administration & dosage*; D004036:Diet, Atherogenic; D005230:Fatty Acids, Nonesterified / Q000097:blood; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000648:ultrastructure; D009132:Muscles / Q000098:blood supply*; D051381:Rats; D011919:Rats, Inbred Strains; D014280:Triglycerides / Q000097:blood
D002791:Cholesterol, Dietary; D005230:Fatty Acids, Nonesterified; D014280:Triglycerides; D002784:Cholesterol