Effects of cigarette smoking on the ultrastructure of rat thoracic aorta and its ability to produce prostacyclin.

Following exposure of rats to graded doses of fresh cigarette smoke, the aortic endothelium examined by scanning electron microscopy regularly showed alterations. These essentially consisted of areas of blebbing and microvillus-like projections from the luminal surface, and the presence in the majority of cases, of micro-thrombi in the low shear areas just proximal to intercostal branches. Aortas from rats exposed to smoke showed a reduction in prostacyclin production in vitro and platelets from these animals aggregated more readily than did those of controls.