scholarly journals Inhibitory effect of beauvericin on a high K+-induced tonic contraction in guinea-pig taenia coli.

1987 ◽  
Vol 45 (3) ◽  
pp. 317-325 ◽  
Author(s):  
Shinjiro NAKAJYO ◽  
Kiyomi MATSUOKA ◽  
Tomohiro KITAYAMA ◽  
Yutaka YAMAMURA ◽  
Kazumasa SHIMIZU ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Inhibitory Effect ◽  
Tonic Contraction ◽  
Taenia Coli ◽  
High K

scholarly journals Inhibitory Effect of Beauvericin on a High K+-lnduced Tonic Contraction in Guinea-Pig Taenia Coli

1987 ◽  
Vol 45 (3) ◽  
pp. 317-325
Author(s):  
Shinjiro NAKAJYO ◽  
Kiyomi MATSUOKA ◽  
Tomohiro KITAYAMA ◽  
Yutaka YAMAMURA ◽  
Kazumasa SHIMIZU ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Inhibitory Effect ◽  
Tonic Contraction ◽  
Taenia Coli ◽  
High K

Discrimination by nimodipine, but not by nifedipine, between phasic and tonic contractions of guinea-pig taenia coli induced by K+ depolarization

1995 ◽  
Vol 73 (11) ◽  
pp. 1600-1604 ◽  
Author(s):  
Sadaharu Usune ◽  
Takeshi Katsuragi ◽  
Tatsuo Furukawa
Keyword(s):  
Guinea Pig ◽  
Tonic Contraction ◽  
Channel Blockers ◽  
Dependent Manner ◽  
Taenia Coli ◽  
Concentration Dependent Manner ◽  
Phasic Contraction ◽  
High K ◽  
Phasic And Tonic Contraction ◽  
Longitudinal Muscles

Effects of Ca2+ channel blockers, such as nifedipine, nimodipine, gallopamil, verapamil, diltiazem, loperamide, Mn2+ and Ni2+, and papaverine, on contractile responses to K+ depolarization were evaluated in longitudinal muscles of taenia coli isolated from guinea-pig. Depolarization with high K+ solution (K+, 40 mM) produced a biphasic (phasic and tonic) contraction, which was inhibited by the above blockers in a concentration-dependent manner. Ratios of IC50 for the phasic contraction to IC50 for the tonic contraction of nimodipine, verapamil, gallopamil, nifedipine, loperamide, diltiazem, papaverine, Ni2+, and Mn2+ were 516.1, 73.7, 22.0, 6.4, 5.3, 4.9, 1.2, 0.7, and 0.1, respectively, indicating that nimodipine suppressed the tonic contraction more effectively than the phasic contraction. In a fluorescence study with fura 2, K+ depolarization elicited an increase in intracellular free Ca2+, [Ca2+]i, which was coupled with the phasic and tonic contraction. The increases in [Ca2+]i coupled with both types of the contraction were abolished by exposure to Ca2+-free solution. In addition, the increase of [Ca2+]i coupled with the phasic contraction was abolished by nifedipine, 10−7 M, but not by nimodipine, 10−7 M, whereas the increase with the tonic contraction was suppressed by both nifedipine and nimodipine. These findings suggest that the phasic and tonic contractions evoked by K+ depolarization are due to increases in [Ca2+]i via activation of respective nimodipine-resistant and nimodipine-sensitive Ca2+ channels in the longitudinal muscles of the taenia coli. Accordingly, nimodipine, but not nifedipine, appears to be a useful tool for distinguishing between the phasic and tonic contractions.Key words: guinea-pig taenia coli, phasic contraction, tonic contraction, nimodipine, nifedipine, intracellular free Ca2+.

Ca45 uptake and tissue calcium in K-induced phasic and tonic contraction in taenia coli

1964 ◽  
Vol 207 (4) ◽  
pp. 873-876 ◽  
Author(s):  
N. Urakawa ◽  
W. C. Holland
Keyword(s):  
Guinea Pig ◽  
Muscle Contraction ◽  
Significant Rise ◽  
Tonic Contraction ◽  
Taenia Coli ◽  
Free Medium ◽  
Phasic Contraction ◽  
High K ◽  
Tissue Calcium ◽  
Phasic And Tonic Contraction

High-K medium produces a tonic contraction in guinea pig taenia coli. If muscle strips are preincubated in glucose-free medium, K produces only a phasic contraction. A comparison of Ca45 entry and tissue Ca changes in the two responses were made. Both responses are accompanied by an enhanced uptake of Ca45. In addition to an increased Ca45 uptake, a significant rise of tissue Ca was observed during the tonic contraction. No detectable changes in tissue Ca were noted in the phasic contraction. In light of modern theories of muscle contraction, it was proposed that in the phasic contraction, sufficient Ca is released from a cellular site to initiate contraction, whereas in the tonic contraction enough Ca crosses the membrane to initiate contraction. The transmembrane Ca transport involved in the latter response appeared to be dependent on metabolism.

The inhibitory effect of monensin on high K-induced contraction in guinea-pig taenia coli

1982 ◽  
Vol 84 (1-2) ◽  
pp. 25-32 ◽  
Author(s):  
T. Kishimoto ◽  
H. Ozaki ◽  
H. Karaki ◽  
N. Urakawa ◽  
Y. Ishida
Keyword(s):  
Guinea Pig ◽  
Inhibitory Effect ◽  
Taenia Coli ◽  
High K

scholarly journals DUAL ACTIONS OF VANADATE ON HIGH K-INDUCED CONTRACTION IN GUINEA-PIG TAENIA COLI

1982 ◽  
Vol 32 (1) ◽  
pp. 149-157
Author(s):  
Fukiko UEDA ◽  
Tadashi KISHIMOTO ◽  
Hiroshi OZAKI ◽  
Norimoto URAKAWA
Keyword(s):  
Guinea Pig ◽  
Taenia Coli ◽  
High K
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