Increased vascular endothelin-1 gene expression with unaltered nitric oxide synthase levels in fructose-induced hypertensive rats

The present study aimed to investigate whether altered expression levels of endothelin-1 (ET-1) and nitric oxide synthase (NOS) are related to the dev elopment of insulin-resistant hypertension, Male Sprague-Dawley rats were f ed a fructose-rich diet for 5 weeks. Systolic blood pressure significantly increased in fructose-fed rats. While serum free fatty acid (FFA) and plasm a nitrite/nitrate (NOx) levels did not significantly differ between the fru ctose-fed and control groups, plasma insulin and serum triglyceride (TG) co ncentrations significantly increased in the former. ET-1 mRNA expression in the aorta increased to 195% in fructose-fed rats. Neither the protein expr ession of constitutive NOS (cNOS) nor that of inducible NOS (iNOS) were sig nificantly affected by fructose feeding. However, NOx levels in the aorta w ere significantly increased. These results indicate that an increased expre ssion of vascular ET-1 may be causally related to the development of hypert ension in fructose-fed rats. However, an altered role of the vascular nitri c oxide (NO) pathway may not be primarily involved in the development of fr uctose-induced hypertension, Copyright (C) 2001 by W.B. Saunders Company.