Ohashi M, Sato R, Takayanagi I
J Pharmacobiodyn. 1983 Jan;6(1):39-45. doi: 10.1248/bpb1978.6.39.
Pharmacological action of ionophore X537A was studied in taenia coli and aortic strips isolated from rabbit. These isolated smooth muscle preparations contracted by X537A (10(-5)-10(-4) M). A removal of Ca ions from the buffer solution considerably reduced the contraction of taenia coli but not that of aorta. D 600 (methoxyverapamil, 10(-6) M) was without any effect in the contraction of both tissues by X537A (10(-4) M). However, papaverine (10(-4) M) and Aspaminol (1, 1-diphenyl-3-piperidinobutanol hydrochloride, 10(-4) M) inhibited X537A (10(-4) M)-induced contraction markedly in taenia coli but slightly in aorta. Inhibitory effects of these drugs were reversed in taenia coli by increasing Ca ion concentration in buffer solution but not in aorta. X537A (10(-4) M)-induced contraction of aorta was not affected by a pretreatment of rabbit with reserpine and preincubation of the isolated preparations with guanethidine (10(-6) M) or prazosin (10(-7) M). These results suggest that ionophore X537A might produce the contraction through an increase of Ca influx in isolated rabbit taenia coli which are little or not affected by D 600, whereas the contraction of rabbit aorta induced by X537A is mainly due to facilitation of release of Ca sequestered intracellularly.
在从兔分离出的结肠带和主动脉条上研究了离子载体X537A的药理作用。这些分离的平滑肌制剂被X537A（10^(-5)-10^(-4)M）收缩。从缓冲溶液中去除钙离子可显著降低结肠带的收缩，但对主动脉的收缩没有影响。D600（甲氧基维拉帕米，10^(-6)M）对X537A（10^(-4)M）引起的两种组织的收缩均无任何作用。然而，罂粟碱（10^(-4)M）和阿斯帕米诺（1,1-二苯基-3-哌啶丁醇盐酸盐，10^(-4)M）在结肠带中显著抑制X537A（10^(-4)M）诱导的收缩，而在主动脉中抑制作用较弱。通过增加缓冲溶液中的钙离子浓度，这些药物在结肠带中的抑制作用被逆转，但在主动脉中未被逆转。用利血平预处理兔以及将分离的制剂与胍乙啶（10^(-6)M）或哌唑嗪（10^(-7)M）预孵育，均不影响X537A（10^(-4)M）诱导的主动脉收缩。这些结果表明，离子载体X537A可能通过增加钙离子内流在分离的兔结肠带中产生收缩，而D600对其影响很小或没有影响，而X537A诱导的兔主动脉收缩主要是由于促进细胞内储存的钙离子释放。
