@article{oai:miyazaki-u.repo.nii.ac.jp:00000271,
 author = {伊藤, 勝昭 and Ito, Katsuaki and 伊藤, 勝昭 and Ito, Katsuaki and Shimomura, Erika and Iwanaga, Takahiro and Shiraishi, Mitsuya and Shindo, Kazutoshi and Nakamura, Junji and Nagumo, Hiromitsu and Seto, Minoru and Sasaki, Yasuharu and Takuwa, Yoh},
 issue = {3},
 journal = {Journal of Physiology},
 month = {Feb},
 note = {Inhibition of dephosphorylation of the 20 kDa myosin light chain (MLC20) is an important mechanism responsible for Ca2+-sensitization of vascular smooth muscle contraction. We investigated whether this mechanism operates in prostaglandin F2α (PGF2α)-induced contraction of rabbit aortic smooth muscle and, if so, which of protein kinase C (PKC) or Rho kinase contributes to the inhibition of dephosphorylation. In normal medium, PGF2α (10 μM) increased phosphorylation of MLC20 and developed tension. Rho kinase inhibitors fasudil and hydroxyfasudil inhibited these changes, despite having no effect on a phorbol ester-induced MLC20 phosphorylation. After treatment with verapamil or chelation of external Ca2+ with EGTA, PGF2α increased the MLC20 phosphorylation and the tension without an increase in [Ca2+]i, which were both sensitive to fasudil and hydroxyfasudil. ML-9, a MLC kinase inhibitor, quickly reversed the KCl-induced MLC20 phosphorylation and contraction to the resting level. However, fractions of PGF2α-induced contraction and MLC20 phosphorylation were resistant to ML-9 but were sensitive to fasudil. Ro31-8220 (10 μM), a PKC inhibitor, did not affect the MLC20 phosphorylation and the tension caused by PGF2α, excluding the possibility of involvement of PKC in the PGF2α-induced MLC20 phosphorylation. PGF2α increased phosphorylation at Thr654 of the myosin binding subunit (MBS) of myosin phosphatase, which is a target of Rho kinase, and fasudil decreased the phosphorylation. These data suggest that the PGF2α-induced contraction is accompanied by the inhibition of MLC20 dephosphorylation through the MBS phosphorylation by Rho kinase, leading to Ca2+-sensitization of contraction. Besides, an actin-associated mechanism may also be involved in the PGF2α-induced sensitization., The definitive version is available at www.blackwell-synergy.com and www.jphysiol.org .},
 pages = {823--836},
 title = {Essential role of Rho kinase in the Ca2+-sensitazation of prostaglandin F2α-induced contraction of rabbit aortae},
 volume = {546},
 year = {2003},
 yomi = {イトウ, カツアキ and イトウ, カツアキ}
}