Role of calcium ion in effects of ECA on contractive activities of smooth muscles of Oncomelania foot / 中国血吸虫病防治杂志

ABSTRACT

Objective To investigate the relationship between the calcium ion and the effects of ECA on the contraction of the smooth muscles of Oncomelania foot, and explore the mechanism of ECA in decreasing the snail climbing adhesion and increasing snail-killing. Method The in vitro experiment was used to observe the effects of ECA on contraction activities of foot smooth muscles of Oncomelania. Results ECA 5. 0, 10. 0, 20. 0 mg/L. enhanced the resting tension, decreased the contraction range and increased the contraction frequency of the foot smooth muscles of Oncomelania in Ringer's solution with or without Ca2+ , with a characteristic of the dose-dependent, but stronger in solution with Ca2+ than that in solution without Ca2+. Conclusions ECA can enhance the resting tension, decrease the contraction range and increase the contraction frequency of the foot smooth muscles of Oncomelania. This suggested that ECA could be related to increasing the intracellular Ca2+ release and influx of the extracellular Ca2+. This could provide an explanation why ECA decreases the rate of Oncomelania climbing adhesion and enhances snail-killing.