Force-inhibiting effect of Ser/Thr protein phosphatase 2A inhibitors on bovine ciliary muscle.
Force-inhibiting effect of Ser/Thr protein phosphatase 2A inhibitors on bovine ciliary muscle.
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DOI：
10.1540/jsmr.51.10
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Takai A
中科院分区：
文献类型：
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作者：
Ishida M;Takeya K;Miyazu M;Yoshida A;Takai A
睫状肌是一种平滑肌，其特点是对毒蕈碱受体的刺激反应迅速并持续收缩。虽然很明显这些收缩是Ca2+依赖的，但详细的分子机制仍然未知。为了阐明丝氨酸/苏氨酸蛋白磷酸酶2A （PP2A）在纤毛肌收缩中的作用，我们研究了okadaic酸和其他PP2A抑制剂对丙二醇（CCh）和离子霉素诱导的牛纤毛肌条（BCM）收缩的影响。冈田酸对离子霉素诱导的收缩有抑制作用，而对氯化碳诱导的收缩无明显影响。Fostriecin对BCM的收缩有相似的抑制作用。另一方面，rubratoxin A抑制离子霉素和cch诱导的收缩。这些结果表明PP2A至少参与了离子霉素诱导的Ca2+依赖性收缩，并且BCM在cch诱导的收缩中具有独特的调节机制。
Ciliary muscle is a smooth muscle characterized by a rapid response to muscarinic receptor stimulation and sustained contraction. Although it is evident that these contractions are Ca2+-dependent, detailed molecular mechanisms are still unknown. In order to elucidate the role of Ser/Thr protein phosphatase 2A (PP2A) in ciliary muscle contraction, we examined the effects of okadaic acid and other PP2A inhibitors on contractions induced by carbachol (CCh) and ionomycin in bovine ciliary muscle strips (BCM). Okadaic acid inhibited ionomycin-induced contraction, while it did not cause significant changes in CCh-induced contraction. Fostriecin showed similar inhibitory effects on the contraction of BCM. On the other hand, rubratoxin A inhibited both ionomycin- and CCh-induced contractions. These results indicated that PP2A was involved at least in ionomycin-induced Ca2+-dependent contraction, and that BCM had a unique regulatory mechanism in CCh-induced contraction.