| Autor: |
Igawa, Osamu, Kotake, Hiroshi, Hirai, Shozo, Hisatome, Ichiro, Hasegawa, Junichi, Mashiba, Hiroto |
| Zdroj: |
Journal of Pharmacy and Pharmacology; May 1989, Vol. 41 Issue: 5 p311-315, 5p |
| Abstrakt: |
The effects of trimebutine maleate on electrical activity in guinea-pig isolated papillary muscles and rabbit sino-atrial nodes have been studied by means of a standard microelectrode method. In papillary muscles, trimebutine (above 10 μM) decreased the maximum rate of rise (V̇max) and the action potential duration at 90% repolarization (APD90), whereas the resting potential was not significantly altered. As to a decrease in V̇max, trimebutine produced a negative shift of the curve relating V̇maxto the resting potential along the voltage axis. Trimebutine also depressed the slow action potentials of papillary muscles produced by 27 mM K and 0·2 mitt Ba. In spontaneously beating sino-atrial node preparations, trimebutine (above 10 μ) decreased the heart rate, V̇maxand the rate of diastolic depolarization. These results indicate that trimebutine maleate possesses a depressant action on the electrical activities of the fast- and slow-response fibres of the heart mainly due to inhibitions of both fast Na+ and slow Ca2+channels. |
| Databáze: |
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