钙离子拮抗剂对绵羊十二指肠自发运动的影响。

The effect of Ca2+ antagonists on spontaneous motility from sheep duodenum.

作者信息

Murillo M D, Plaza M A, de Pedro M J, Arruebo M P

机构信息

Departamento de Farmacología y Fisiología (Fisiología), Facultad de Veterinaria, Universidad de Zaragoza, Spain.

出版信息

J Pharm Pharmacol. 1994 Feb;46(2):138-40. doi: 10.1111/j.2042-7158.1994.tb03757.x.

DOI:10.1111/j.2042-7158.1994.tb03757.x

PMID:8021803

Abstract

Longitudinal smooth muscle of the sheep duodenum showed a rhythmic spontaneous activity with an average frequency of 5.6 +/- 0.55 phasic movements min-1 and a mean value of the amplitude of phasic contractions of 0.956 +/- 0.1 g. When the strips were incubated in Ca(2+)-free medium, the spontaneous motility amplitude (SMA) was reduced to 37 +/- 8.2% of control values. In Ca(2+)-free medium plus EDTA (1 or 2 mM), the SMA was strongly reduced to 21.9 +/- 8.3 and 1.8 +/- 1.8%, respectively. Verapamil, nifedipine and diltiazem diminished the SMA. The EC50 value for verapamil was 10(-9) M, whereas that for diltiazem was 2 x 10(-9) M and for nifedipine was 3 x 10(-14) M. Trifluoperazine and TMB-8 reduced the SMA with EC50 values of 7 x 10(-6) and 3 x 10(-5) M, respectively. The spontaneous activity in the sheep duodenum seemed to be mediated by influx extracellular Ca2+, which enters through potential-dependent channels and intracellular Ca2+ release.

摘要

绵羊十二指肠的纵行平滑肌呈现出节律性自发活动，平均频率为5.6±0.55次相性运动/分钟，相性收缩幅度的平均值为0.956±0.1克。当肠条在无钙培养基中孵育时，自发运动幅度（SMA）降至对照值的37±8.2%。在无钙培养基加EDTA（1或2 mM）中，SMA分别强烈降至21.9±8.3%和1.8±1.8%。维拉帕米、硝苯地平和地尔硫卓降低了SMA。维拉帕米的EC50值为10^(-9) M，地尔硫卓的EC50值为2×10^(-9) M，硝苯地平的EC50值为3×10^(-14) M。三氟拉嗪和TMB-8降低了SMA，EC50值分别为7×10^(-6) M和3×10^(-5) M。绵羊十二指肠的自发活动似乎由细胞外Ca2+内流介导，Ca2+通过电压依赖性通道进入并引起细胞内Ca2+释放。