Shinjiro Nakajyo

Learn More
Effects of phorbol ester, 12-deoxyphorbol 13-isobutyrate (DPB), on muscle tension and cytosolic Ca2+ ([Ca2+]i) level was investigated in rat anococcygeus muscle in comparison with other smooth muscles. 1) DPB (10(-6) M) induced a large contraction and an elevation of [Ca2+]i level in rat aorta and small and rhythmic changes in tension and [Ca2+]i level in(More)
We have demonstrated that the relaxing mechanism of papaverine in phasic muscles such as ileum, urinary bladder, and uterus is different from tonic muscles such as aorta. In this study, we examined the inhibitory mechanism of papaverine on carbachol (CCh)-induced contraction in the bovine trachea. Papaverine inhibited muscle contraction and increase in(More)
Effects of various selective phosphodiesterase (PDE) inhibitors on muscle contractility and cyclic nucleotide contents in guinea pig taenia coli were investigated. Forskolin and sodium nitroprusside inhibited carbachol (CCh)-induced contraction in a concentration-dependent manner. Various selective PDE inhibitors, vinpocetine (type 1), erythro(More)
A contractile property of phenylephrine (PE), alpha 1 agonist, on rat anococcygeus muscle was compared with that on rat aorta by simultaneously measuring changes in intracellular Ca2+ ([Ca2+]i) level and muscle tension. (1) PE (0.1-30 microM) and high K+ induced a sustained increases in [Ca2+]i level and muscle tension of both the muscles. (2) An(More)
The effects of various selective phosphodiesterase (PDE) inhibitors on muscle contractility in guinea pig ileal longitudinal smooth muscle were investigated. 1) 3-Isobutyl-1-methyl xanthine (IBMX) or zaprinast markedly inhibited the high K(+)- or carbachol (CCh)-induced contraction and increased cGMP content of the muscle strip in a concentration-dependent(More)
The effects of various selective phosphodiesterase (PDE) inhibitors on muscle contractility and cyclic nucleotide contents in the guinea pig gall bladder were investigated. Various selective PDE inhibitors, vinpocetine (type 1), erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA, type 2), milrinone (type 3), Ro20-1724 (type 4), and zaprinast (type 5), inhibited(More)
An inhibitory effect of beauvericin, a cyclodepsipeptide, on a high K+-induced contraction in guinea-pig taenia coli was compared with those of verapamil, an organic Ca2+ antagonist, and monensin, an inhibitor of mitochondrial respiration. Beauvericin (10(-5) M), verapamil (5 x 10(-7) M) or monensin (10(-6) M) markedly inhibited the tonic contraction, while(More)
Papaverine (0.3-100 microM) more potently inhibited phenylephrine (1 microM)-induced contraction than 65 mM K+-induced contraction of the aorta, while it equally inhibited contractions induced by 65 mM K+ and carbachol (1 microM) in ileal smooth muscle. In phenylephrine-treated aorta, papaverine (1-10 microM) increased the cAMP and cGMP content. However, in(More)
In this study, we examined the inhibitory mechanism of monensin on high K+-induced contraction in guinea-pig urinary bladder. The relaxant effect of monensin (0.001 - 10 microM) was more potent than those of NaCN (100 microM - 1 mM) and forskolin (3 - 10 microM). Monensin (0.1 microM), NaCN (300 microM), or forskolin (10 microM) inhibited high K+-induced(More)
Extracts containing gymnemic acids, which were extracted from the leaves of Gymnema sylvestre (GS) as nine fractions, were evaluated for their effects on a high K(+)-induced contraction of guinea-pig ileal longitudinal muscles, on glucose transport mediated by the difference of glucose-evoked transmural potential difference (delta PD) in the inverted(More)