title: 28-Day hindlimb unweighting reduces expression of Rho kinase and inhibits its effects in femoral artery of rat.
abstract: Previous studies have demonstrated inconsistent roles of Rho kinase (ROCK) in the decreased vasoconstriction of rat hindquarter vessels induced by hindlimb unweighting (HU). The present study was designed to determine the unclear role of ROCK in the mediation of HU-induced decreased femoral arterial vasoconstriction. 28-day HU rat was adopted as the animal model. With or without Y-27632, a ROCK inhibitor, isometric force of femoral artery was measured. The expression of ROCK and its effects on downstream targets were also examined. Results showed that (1) HU caused a significant decrease of the phenylephrine (PE)-evoked and potassium chloride (KCl)-evoked femoral arterial vasoconstriction (P < 0.05), confirming the functional findings by previous studies. (2) Inhibition of ROCK with Y-27632 produced an equal reduction of the vasoconstriction in CON and HU. (3) HU significantly decreased ROCK II expression and the effects of ROCK on myosin light-chain phosphatase (MLCP) and MLC (P < 0.05), but increased p65 nuclear translocation (P < 0.05) and inducible nitric oxide synthase (iNOS) expression (P < 0.05). (4) HU significantly (P < 0.05) increased NO production in femoral arteries, with Y-27632 significantly (P < 0.01) amplifying this effect. These findings have revealed that 28-day HU reduced the expression and effects of ROCK on downstream targets both directly (MLCP and MLC) and possibly indirectly (NF-κB/iNOS/NO pathway) related to vasoconstriction in femoral arteries.
authors.affiliation: Department of Aerospace Physiology, Fourth Military Medical University, No. 169, Changle West Road, Xi'an, 710032, China.
authors.forename: Zhong-Chao
authors.initials: ZC
authors.lastname: Wang
authors.forename: Huan
authors.initials: H
authors.lastname: Liu
authors.forename: Yun-Gang
authors.initials: YG
authors.lastname: Bai
authors.forename: Jin-Wen
authors.initials: JW
authors.lastname: Yu
authors.forename: Hai-Jun
authors.initials: HJ
authors.lastname: Zhang
authors.forename: Yao-Ping
authors.initials: YP
authors.lastname: Cheng
authors.forename: Jun-Xiang
authors.initials: JX
authors.lastname: Bao
authors.forename: Xin-Ling
authors.initials: XL
authors.lastname: Ren
authors.forename: Hong-Zhe
authors.initials: HZ
authors.lastname: Ma
authors.forename: Jin
authors.initials: J
authors.lastname: Ma
mesh_terms: D000577:Amides / Q000494:pharmacology; D000818:Animals; D005263:Femoral Artery / Q000187:drug effects / Q000502:physiology*; D019417:Hindlimb Suspension; D008297:Male; D016328:NF-kappa B / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D017207:Rats, Sprague-Dawley; D014661:Vasoconstriction / Q000187:drug effects; D018474:Weightlessness Simulation; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D000577:Amides; D016328:NF-kappa B; D047428:Protein Kinase Inhibitors; D011725:Pyridines; C108830:Y 27632; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D054460:rho-Associated Kinases