Effect of vitamin E on vascular integrity in cholesterol-fed guinea pigs.
This study was designed to clarify the effects of vitamin E on the alterations in proteoglycan distribution and vascular permeability, which were examined by immunohistochemical and ultrastructural techniques in the aortas of cholesterol-fed guinea pigs. The animals were divided into three groups: a control group, a cholesterol group, and a vitamin E group. Serum levels of cholesterol, triglyceride, low-density lipoprotein, high-density lipoprotein, and thiobarbituric acid-reactive substances were measured. An increase in thiobarbituric acid-reactive substances was observed in the cholesterol group compared with control and vitamin E groups. Intimal atheromatous lesions of the aorta were significantly decreased in the vitamin E group compared with the cholesterol group. Histochemically, an increased distribution of proteoglycans such as chondroitin, dermatan, and heparan sulfates and ruthenium red reaction products in the intima; decreased glycocalyx on the endothelial surface; and increased permeability to horseradish peroxidase were revealed in the cholesterol group compared with the vitamin E group. Hypercholesterolemia, resulting in superoxide production, may have contributed to the endothelial damage and increased permeability to plasma proteins and lipids in the vascular wall of the cholesterol group. However, vitamin E administration inhibited lipid deposition and development of this abnormal permeability associated with an irregular distribution of proteoglycan. These results suggest that vitamin E preserves the morphological and functional integrity of the vascular wall and may contribute to the inhibition of atherogenesis in cholesterol-fed guinea pigs.
Qiao
Y
Y
Department of Pathology, Nippon Medical School, Tokyo, Japan.
Yokoyama
M
M
Kameyama
K
K
Asano
G
G
D000818:Animals; D001011:Aorta / Q000503:physiopathology* / Q000648:ultrastructure; D001161:Arteriosclerosis / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D002199:Capillary Permeability / Q000187:drug effects; D002784:Cholesterol / Q000097:blood; D002791:Cholesterol, Dietary / Q000008:administration & dosage*; D002809:Chondroitin Sulfates / Q000032:analysis; D003871:Dermatan Sulfate / Q000032:analysis; D006168:Guinea Pigs; D006497:Heparan Sulfate / Q000032:analysis; D007150:Immunohistochemistry; D008074:Lipoproteins / Q000097:blood; D008854:Microscopy, Electron; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014810:Vitamin E / Q000494:pharmacology* / Q000627:therapeutic use
D002784:Cholesterol; D002791:Cholesterol, Dietary; D002809:Chondroitin Sulfates; D003871:Dermatan Sulfate; D006497:Heparan Sulfate; D008074:Lipoproteins; D017392:Thiobarbituric Acid Reactive Substances; D014810:Vitamin E