title: Fluoride induces vascular contraction through activation of RhoA/Rho kinase pathway in isolated rat aortas.
abstract: We hypothesized that fluoride induces vascular contraction through activation of the RhoA/Rho kinase pathway in isolated rat aortas. Rat aortic rings were mounted in organ baths and contracted with sodium fluoride (NaF). We measured the amount of GTP-RhoA as well as vascular tension. We also determined the level of phosphorylation of the myosin light chain (MLC(20)), myosin phosphatase targeting subunit 1 (MYPT1) and PKC-potentiated inhibitory protein for heterotrimeric MLCP of 17kDa (CPI17). In both physiological salt solution and Ca(2+)-free solution, NaF increased vascular tension and MLC(20) phosphorylation in dose-dependent manners. NaF increased not only phosphorylation level of MYPT1(Thr855) and CPI17(Thr38), but also the amount of GTP-RhoA. Both H1152 and Y27632, inhibitors of Rho kinase, but not Ro31-8220, an inhibitor of PKC, attenuated NaF-induced contraction and phosphorylation level of MLC(20), MYPT1(Thr855) and CPI17(Thr38). In conclusion, fluoride induces vascular contraction through activation of the RhoA/Rho kinase pathway.
authors.affiliation: Department of Pharmacology, Kyungpook National University School of Medicine, Daegu 700-422, Republic of Korea.
authors.forename: Enyue
authors.initials: E
authors.lastname: Yang
authors.forename: Su Bun
authors.initials: SB
authors.lastname: Jeon
authors.forename: Inji
authors.initials: I
authors.lastname: Baek
authors.forename: Min-Ji
authors.initials: MJ
authors.lastname: Song
authors.forename: Young-Ran
authors.initials: YR
authors.lastname: Yoon
authors.forename: In Kyeom
authors.initials: IK
authors.lastname: Kim