Gardner D R, Brezden B L
Can J Physiol Pharmacol. 1984 Mar;62(3):282-7. doi: 10.1139/y84-044.
Praziquantel (1.6 X 10(-6) M), a new anthelmintic drug, was shown to produce a sustained contracture in the penis retractor muscle of the freshwater snail Lymnaea stagnalis. Calcium-free saline greatly reduced the magnitude and duration of the praziquantel contractures if the preparation had been previously exposed to praziquantel. The praziquantel contracture in zero-calcium saline was abolished if the preparation was pretreated with successive applications of 2 X 10(-2) M caffeine. Lanthanum (1.0 mM) in zero-calcium saline prevented the contractures normally produced by 30 mM potassium saline, but did not prevent the praziquantel contracture. In normal saline, however, 1.0 mM lanthanum greatly reduced the magnitude of a praziquantel-induced contracture. We conclude that praziquantel increases sarcolemmal calcium permeability and releases calcium from intracellular stores in Lymnaea stagnalis smooth muscle.
吡喹酮（1.6×10⁻⁶ M），一种新型抗蠕虫药，已被证明能使淡水蜗牛椎实螺的阴茎牵缩肌产生持续性挛缩。如果标本先前已接触过吡喹酮，无钙生理盐水会大大降低吡喹酮挛缩的幅度和持续时间。如果标本先用2×10⁻² M咖啡因连续处理，在无钙生理盐水中的吡喹酮挛缩就会消失。无钙生理盐水中的镧（1.0 mM）可阻止30 mM钾生理盐水通常产生的挛缩，但不能阻止吡喹酮挛缩。然而，在正常生理盐水中，1.0 mM镧会大大降低吡喹酮诱导的挛缩幅度。我们得出结论，吡喹酮可增加椎实螺平滑肌肌膜对钙的通透性，并从细胞内储存中释放钙。
