Uncoupling of force and myosin light chain phosphorylation produced by slow stretch in vascular smooth muscle.

血管平滑肌缓慢拉伸产生的力和肌球蛋白轻链磷酸化的解偶联。

• 批准号: 10670093
• 负责人: OBARA Kazuo
• 金额: $ 1.98万
• 依托单位: Department of Pharmacology, Faculty of Pharmaceutical Sciences, University of Shizuoka
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10670093/
• 关键词: dog; vascular smooth muscle; basilar artery; stretch stimulation; myosin phosphorylation; protein kinase C; myosin phosphatase; Rho; 収縮

Relationship between force and myosin light chain (MLC) phosphorylation in slow stretch-induced contraction in canine basilar artery was investigated. In the presence of tetraethyl-ammonium (5 mM), slow stretch at a rate of 1 mm/sec up to 1.5 times initial muscle length during a stimulus period of 15 min produced an increase in multiple phosphorylated MLC species (at least mono-, di- and tri-phosphorylated species) without any apparent contraction, indicating uncoupling of force and MLC phosphorylation. Slow stretch also increased translocation of protein kinase C (PKC)-α and PKC-δ from the cytosol to the membrane fraction. The MLC phosphorylation was inhibited by nicardipine (a 1,4-dihydropyridine Ca^<2+> channel blocker), ML-9 (an inhibitor of myosin light chain kinase) or calphostin C (a cPKC/nPKC inhibitor) to about 50% of that in drug-untreated artery. Y-27632 ( a Rho-kinase inhibitor) abolished the MLC phosphorylation. In contrast, rottlerin (5 μM, a putative inhibitor of PKC-δ) had no apparent effect on MLC phosphorylation. The translocation of PKC-α was inhibited by only calphostin C, and that of PKC-δ was attenuated by calphostin C, Y-27632 or rottlerin. Okadaic acid (an inhibitor of phosphatase) inhibited 80 mM KCl-induced contraction, but it increased multiple phosphorylated MLC species.Considering that the translocation of PKC-α and δ is important for their activation, the present results suggest that Rho/Rho-kinase activity and PKC other than PKC-δ are involved in MLC phosphorylation without contraction.

研究了牵张收缩犬基底动脉时肌球蛋白轻链（MLC）磷酸化与力的关系。在四乙基铵（5 mM）的存在下，在15分钟的刺激期期间以1 mm/sec的速率缓慢拉伸至初始肌肉长度的1.5倍产生多个磷酸化MLC种类（至少单磷酸化、二磷酸化和三磷酸化种类）的增加，而没有任何明显的收缩，表明力和MLC磷酸化的解偶联。缓慢牵张还增加了蛋白激酶C（PKC）-α和PKC-δ从胞质向膜组分的移位。尼卡地平（1，4-二氢吡啶类Ca^2+通道阻断剂）、ML-9（肌球蛋白轻链激酶抑制剂）和calphostin C（cPKC/nPKC抑制剂）可抑制MLC的磷酸化，抑制程度约为未给药组的50%。Y-27632（Rho激酶抑制剂）消除MLC磷酸化。相反，rottlerin（5 μM，一种推定的PKC-δ抑制剂）对MLC磷酸化没有明显影响。仅Calphostin C能抑制PKC-α的转位，而Calphostin C、Y-27632和rottlerin则能减弱PKC-δ的转位。Okadaic acid（一种磷酸酶抑制剂）抑制80 mM KCl诱导的MLC收缩，但增加了MLC的多种磷酸化种类，考虑到PKC-α和δ的转位在其激活中起重要作用，本研究结果表明，Rho/Rho激酶活性和PKC（而不是PKC-δ）参与了MLC的磷酸化而不收缩。

项目成果

K.Obara,M.Koide,T.Ishikawa,Y.Tanabe,K.Nakayama: "Protein kinase Cδ but not PKCε activity is involved in contractile potentiation by endothelin-1in the porcine coronary artery"Journal of Cardiovascular Pharmacology. (印刷中). (2000)

K. Obara、M. Koide、T. Ishikawa、Y. Tanabe、K. Nakayama：“猪冠状动脉内皮素 1 的收缩增强作用涉及蛋白激酶 Cδ，但 PKCε 活性不参与”《心血管药理学杂志》（出版中）。 ）（2000）。

K.Obara,K.Nobe,H.Nobe,M.S.Kolodncy,P.de Lanerollc,R.J.Paul: "Effects of microtubules and microfilaments on [Ca^<2+>]_i and contractility in a reconstituted fibroblast fiber."American Journal of Physiology. 279. C785-C796 (2000)

K.Obara,K.Nobe,H.Nobe,M.S.Kolodncy,P.de Lanerollc,R.J.Paul：“微管和微丝对 [Ca^<2>]_i 和重建成纤维细胞收缩性的影响。”美国杂志

K.Obara,M.Saito,A.Yamanaka,M.Uchino and K.Nakayama: "Involvement of different activator Ca^<2+> in the rate-dependent stretch-induced contractions of canine basilar artery."Japanese Journal of Physiology. (印刷中). (2001)

K. Obara、M. Saito、A. Yamanaka、M. Uchino 和 K. Nakayama：“不同激活剂 Ca^<2+> 参与犬基底动脉的速率依赖性拉伸诱导收缩。”《日本生理学杂志》 （正在出版）。

K.Nob,H.Nobe,K.Obara,R.J.Paul: "Preferential role of intracellular Ca^<2+> stores in regulation of isometric force in NIH 3T3 fibroblast fibers."Journal of Physiology. 529. 669-679 (2000)

K.Nob，H.Nobe，K.Obara，R.J.Paul：“细胞内Ca^2存储在NIH 3T3成纤维细胞纤维等长力调节中的优先作用。”生理学杂志。

小原一男,小出昌代,石川智久,田辺由幸,中山貢一: "メカノセンサー機構の実体と機能-新しい視点からの創薬への展望-:5.イヌ脳底動脈における張力発生を伴わない伸展誘発性ミオシン軽鎖のリン酸化について"日本薬理学雑誌. 116. 354-355 (2000)

Kazuo Ohara、Masayo Koide、Tomohisa Ishikawa、Yoshiyuki Tanabe、Koichi Nakayama：“机械传感器机制的现实和功能 - 从新角度进行药物发现的前景 -：5. 犬基底动脉中不产生张力的延伸” 关于诱导磷酸化肌球蛋白轻链”日本药理学杂志 116. 354-355 (2000)。