Goodman F R, Weiss G B, Karaki H, Nakagawa H
Eur J Pharmacol. 1987 Jan 6;133(1):111-7. doi: 10.1016/0014-2999(87)90212-3.
The effects of high potassium, carbachol and histamine on tension responses and 45Ca fluxes in tracheal smooth muscle were examined. Calcium depletion or nitrendipine (10(-8) M) inhibited potassium-induced contractile responses more than those obtained with either histamine or carbachol, whereas Sr2+ inhibited mainly responses to histamine or carbachol. The Ca2+ entry facilitator, CGP 28392 (3 X 10(-6) M), potentiated contractions induced only by potassium. Uptake of 45Ca in guinea pig tracheal muscle can be separated into high and low affinity components. The 45Ca efflux rate from tracheal muscle into a La3+-substituted solution was over four-fold higher than in other smooth muscles. Potassium, carbachol and histamine induced sustained increases in 45Ca efflux into solutions containing 1.5 mM Ca2+; only transient increases in 45Ca efflux with carbachol and histamine were obtained after Ca2+ depletion. These agonists elicit contractile responses in tracheal muscle by selectively mobilizing different cellular and extracellular Ca2+ components.
研究了高钾、卡巴胆碱和组胺对气管平滑肌张力反应及45Ca通量的影响。钙耗竭或尼群地平（10(-8) M）对钾诱导的收缩反应的抑制作用比对组胺或卡巴胆碱诱导的收缩反应的抑制作用更强，而Sr2+主要抑制对组胺或卡巴胆碱的反应。Ca2+内流促进剂CGP 28392（3×10(-6) M）仅增强由钾诱导的收缩。豚鼠气管肌肉中45Ca的摄取可分为高亲和力和低亲和力成分。气管肌肉中45Ca向La3+替代溶液的外流速率比其他平滑肌高出四倍多。钾、卡巴胆碱和组胺诱导45Ca向含1.5 mM Ca2+溶液中的外流持续增加；钙耗竭后，卡巴胆碱和组胺仅引起45Ca外流的短暂增加。这些激动剂通过选择性动员不同的细胞内和细胞外Ca2+成分在气管肌肉中引发收缩反应。
