Force-inhibiting effect of Ser/Thr protein phosphatase 2A inhibitors on bovine ciliary muscle
-
- Ishida Minori
- Department of Physiology, Asahikawa Medical University, Hokkaido, Japan
-
- Takeya Kosuke
- Department of Physiology, Asahikawa Medical University, Hokkaido, Japan
-
- Miyazu Motoi
- Department of Physiology, Asahikawa Medical University, Hokkaido, Japan
-
- Yoshida Akitoshi
- Department of Physiology, Asahikawa Medical University, Hokkaido, Japan
-
- Takai Akira
- Department of Physiology, Asahikawa Medical University, Hokkaido, Japan
Search this article
Abstract
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. <br>
Journal
-
- Journal of Smooth Muscle Research
-
Journal of Smooth Muscle Research 51 (0), 10-21, 2015
Japan Society of Smooth Muscle Research
