Abstract
We investigated the endothelial function and oxidative stress in Dahl salt-sensitive rats with risk factors for atherosclerosis, i.e. hypertension and/or hypercholesterolemia. 109 rats were randomly assigned to four experimental diet groups; control (MF), high-salt (S), high-cholesterol (C), and combination of high-salt and high-cholesterol (SC), taking these diets ad libitum for 8 weeks. After physiological examination every other week, we observed the distribution of NO production and eNOS expression in endothelial cells around aorto-renal bifurcation of rats by using confocal laser scanning microscopy (LEICA TCS NT), and also measured plasma NOx and superoxide production in each organ. NO production was suppressed at the cranial portion of aorto-renal bifurcation regardless of diet groups. Plasma NOx was increased in the risk factor groups. Superoxide production increased in kidney and abdominal aorta in SC. In groups C and SC fatty liver was observed, and in groups S and SC cardiac hypertrophy and renal hypertrophy was induced. In risk factor groups, NO production was suppressed at the cranial portion of aorto-renal bifurcation, which is atheroma prone portion, same as a control group. Therefore local suppression of NO production in risk factor groups contributed to the localization of atherosclerosis. We conclude that NO and superoxide might be involved in the initiation and development of atherosclerosis. [Jpn J Physiol 54 Suppl:S99 (2004)]
