Quantitative aspects of arterial endothelium in the adult Sprague-Dawley rat.
Ultrastructural features of aortic and carotid artery endothelium were investigated using transmission electron microscopy and freeze-fracture methodologies. Morphometric analysis was conducted to quantitate the pinocytotic vesicle population within endothelial cells. A significantly greater volume fraction of vesicles and vesicles/micrometer 3 was found in the carotid artery. The membrane-bound vesicles in the endothelium of the aorta and carotid artery exhibited a greater fractional area than has been reported for capillary endothelium. These findings may indicate a specialized function of the vesicles in large arteries for increasing the total plasma membrane surface area in response to high transmural pressures.
D000818:Animals; D001013:Aorta, Thoracic / Q000033:anatomy & histology; D001158:Arteries / Q000033:anatomy & histology*; D002339:Carotid Arteries / Q000033:anatomy & histology; D004727:Endothelium / Q000033:anatomy & histology; D008297:Male; D008855:Microscopy, Electron, Scanning; D010873:Pinocytosis; D051381:Rats; D011919:Rats, Inbred Strains