Scanning electron microscopy of the aorta.

The folds of the intimal surface do not represent the endothelia. Rather, they are produced by tissue shrinkage occurring during preparation, with the shrinking process proceeding in the arteriosclerotic bed differing from that in the normal vessel wall. Consequently, the surface appearance, or texture, of arteriosclerotic beds is different from that of the normal vessel wall. Administration of angiotensin results in the deposition of parietal microthrombi and fibrin filaments as well as in the adhesion of mononuclear leukocytes to the inner coat of the vessel.