Characteristics of vasorelaxation responses in a rat model of metabolic syndrome.
1. Abnormal vasorelaxation responses are seen in the context of various disease states, including obesity, hypertension, hyperlipidemia and diabetes. Metabolic syndrome, which is characterized by the concomitant presence of all of these disease states, develops spontaneously in the SHR/NDmcr-cp (cp/cp) rat (SHR-cp). The goal of the present study was to determine whether abnormal vasorelaxation responses were present with metabolic syndrome. 2. Acetylcholine-induced endothelial-dependent relaxation was significantly enhanced in aortas isolated from SHR-cp at the age of 18 weeks when compared to that from control rats [lean littermates SHR/NDmcr-cp (+/+) (SHR)]. In contrast, endothelium-independent relaxation in response to sodium nitroprusside was equally attenuated in the two rat groups compared with normotensive Wistar-Kyoto rats. 3. These results suggest that endothelial nitric oxide (NO) production increased in the aorta of SHR-cp as compared to SHR. This may compensate for the concomitant impairment in the NO-mediated relaxation response in smooth muscle cells, that probably results from hypertension. Enhanced NO production may result from a variety of factors, including increases in oxidative stress in the context of the metabolic syndrome.
Kagota
Satomi
S
Department of Pharmacology, School of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Japan. skagota@mwu.mukogawa-u.ac.jp
Tanaka
Naoko
N
Kubota
Yoko
Y
Yamaguchi
Yu
Y
Nakamura
Kazuki
K
Kunitomo
Masaru
M
Shinozuka
Kazumasa
K
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology; D001013:Aorta, Thoracic / Q000187:drug effects / Q000503:physiopathology*; D006152:Cyclic GMP / Q000502:physiology; D004195:Disease Models, Animal; D006973:Hypertension / Q000503:physiopathology; D066298:In Vitro Techniques; D008297:Male; D024821:Metabolic Syndrome / Q000503:physiopathology*; D009569:Nitric Oxide / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology*; D014665:Vasodilator Agents / Q000494:pharmacology
D000959:Antihypertensive Agents; D020030:Nitric Oxide Donors; D014665:Vasodilator Agents; D009599:Nitroprusside; D009569:Nitric Oxide; D006152:Cyclic GMP; D000109:Acetylcholine