Carbohydrate cytochemistry of the endothelium lining the splenic blood vessels in the rat.

In the endothelial cells lining the rat splenic blood vessels, neutral carbohydrates were studied by means of combined periodic acid-thiocarbohydrazide-silver protein (PA-TCH-SP) and alpha-amylase digestion methods. In the endothelial cells lining the central and follicular arteries of the spleen, the neutral glycoconjugate-containing surface coat of the luminal plasma membrane and related pinocytotic invaginations and vesicles in the apical cytoplasm were strikingly distinguished, as compared with those in the cells lining the splenic sinuses. In contrast, cytoplasmic glycogen particles in the sinus endothelial cells were apparently larger in amount than those in the arteriolar endothelial cells. Such cytochemical variations of neutral carbohydrates with the arteriolar and venous vessels of the rat spleen were discussed with special reference to varying cytophysiological functions of the endothelial cells with the different segments of the splenic blood vessels.