Impaired endothelium-mediated relaxation in isolated cerebral arteries from insulin-resistant rats

1 Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157-1083; and 2 Institute of Human Physiology and Clinical Experimental Research, Semmelweis University, Budapest, Hungary 1082 Insulin resistance (IR) impairs vascular responses in peripheral arteries. However, the effects of IR on cerebrovascular control mechanisms are completely unexplored. We examined the vascular function of isolated middle cerebral arteries (MCAs) from fructose-fed IR and control rats. Endothelium-dependent vasodilation elicited by bradykinin (BK) was reduced in IR compared with control MCAs. Maximal dilation to BK (10 6 M) was 38 ± 3% ( n = 13) in control and 19 ± 3% ( n = 10) in IR arteries ( P