丹曲林可阻断钾离子在回肠纵行平滑肌中引发的强直性收缩和钙内流。

Dantrolene blocks the tonic contraction and calcium influx evoked by K+ in ileal longitudinal smooth muscle.

Nasu T, Oosako H, Shibata H

Department of Veterinary Pharmacology, Faculty of Agriculture, Yamaguchi University, Japan.

Gen Pharmacol. 1996 Apr;27(3):513-7. doi: 10.1016/0306-3623(95)00102-6.

Abstract

Dantrolene (10(-5)-10(-4) M) reduced the K+ (60 mM) tonic response in accordance with decreased Ca2+ uptake, as determined by La method, more than the phasic in ileal muscle. 2. After saponin-treatment of the fibers, which leaves the Ca2+ storage sites intact, dantrolene had only a slight effect on the caffeine-induced contraction. In Triton-X-100-treated fibers, in which the Ca2+ release sites are destroyed, dantrolene did not affect the Ca(2+)-induced contraction. 3. The results suggest that dantrolene inhibited the high-K(+)-induced tonic response mainly by inhibiting Ca2+ influx via voltage-dependent Ca2+ channels in ileum without affecting contractile elements. In contrast, dantrolene had only a slight effect on the intracellular Ca2+ release from caffeine-sensitive release sites.

摘要

丹曲林（10⁻⁵ - 10⁻⁴ M）可降低K⁺（60 mM）引起的强直性反应，根据镧法测定，其与Ca²⁺摄取减少相关，在回肠肌肉中对强直性反应的降低作用大于对相位性反应的降低作用。2. 在用皂苷处理纤维后，Ca²⁺储存位点保持完整，丹曲林对咖啡因诱导的收缩只有轻微影响。在用Triton-X-100处理的纤维中，Ca²⁺释放位点被破坏，丹曲林不影响Ca²⁺诱导的收缩。3. 结果表明，丹曲林主要通过抑制回肠中电压依赖性Ca²⁺通道的Ca²⁺内流来抑制高K⁺诱导的强直性反应，而不影响收缩成分。相比之下，丹曲林对咖啡因敏感释放位点的细胞内Ca²⁺释放只有轻微影响。