title: Hypothermia Inhibits Endothelium-Independent Vascular Contractility via Rho-kinase Inhibition.
abstract: The present study was undertaken to investigate the influence of hypothermia on endothelium-independent vascular smooth muscle contractility and to determine the mechanism underlying the relaxation. Denuded aortic rings from male rats were used and isometric contractions were recorded and combined with molecular experiments. Hypothermia significantly inhibited fluoride-, thromboxane A2-, phenylephrine-, and phorbol ester-induced vascular contractions regardless of endothelial nitric oxide synthesis, suggesting that another pathway had a direct effect on vascular smooth muscle. Hypothermia significantly inhibited the fluoride-induced increase in pMYPT1 level and phorbol ester-induced increase in pERK1/2 level, suggesting inhibition of Rho-kinase and MEK activity and subsequent phosphorylation of MYPT1 and ERK1/2. These results suggest that the relaxing effect of moderate hypothermia on agonist-induced vascular contraction regardless of endothelial function involves inhibition of Rho-kinase and MEK activities.
authors.affiliation: Department of Anatomy, College of Medicine, Chung-Ang University, Seoul 06974, Republic of Korea.
authors.forename: Yoon Hee
authors.initials: YH
authors.lastname: Chung
authors.affiliation: Department of Pathology, College of Medicine, Chung-Ang University, Seoul 06974, Republic of Korea.
authors.forename: Keon Woong
authors.initials: KW
authors.lastname: Oh
authors.affiliation: Department of Pharmacology, College of Medicine, Chung-Ang University, Seoul 06974, Republic of Korea.
authors.forename: Sung Tae
authors.initials: ST
authors.lastname: Kim
authors.affiliation: Department of Pathology, College of Medicine, Chung-Ang University, Seoul 06974, Republic of Korea.
authors.forename: Eon Sub
authors.initials: ES
authors.lastname: Park
authors.affiliation: Department of Pharmacology, College of Pharmacy, Catholic University of Daegu, Gyeongsan 38430, Republic of Korea.
authors.forename: Hyun Dong
authors.initials: HD
authors.lastname: Je
authors.affiliation: Department of Pharmacology, College of Pharmacy, Catholic University of Daegu, Gyeongsan 38430, Republic of Korea.
authors.forename: Hyuk-Jun
authors.initials: HJ
authors.lastname: Yoon
authors.affiliation: Department of Pharmacology, College of Pharmacy, Chung Ang University, Seoul 06974, Republic of Korea.
authors.forename: Uy Dong
authors.initials: UD
authors.lastname: Sohn
authors.affiliation: Department of Pharmacology, College of Medicine, Chung-Ang University, Seoul 06974, Republic of Korea.
authors.forename: Ji Hoon
authors.initials: JH
authors.lastname: Jeong
authors.affiliation: Department of Pharmacology, College of Pharmacy, The Catholic University of Korea, Bucheon 14662, Republic of Korea.
authors.forename: Hyen-Oh
authors.initials: HO
authors.lastname: La
keywords: ERK1/2; MYPT1; Rho-kinase; fluoride; hypothermia; phorbol ester