L-N6-苯基异丙基腺苷（L-PIA）对大鼠离体半横膈膜的作用。

The effect of L-N6-phenylisopropyladenosine (L-PIA) on the isolated hemidiaphragm of the rat.

作者信息

Varagić V M, Prostran M

出版信息

J Pharmacol. 1986 Oct-Dec;17(4):707-11.

Abstract

The effect of L-N6-phenylisopropyladenosine (L-PIA) on the maximum tension developed (Td) and the maximum rate of rise of tension (dT/dt max) of the isolated hemidiaphragm of the rat was investigated during direct electrical stimulation. L-PIA itself (0.07-5.5 mumol l-1) did not produce significant changes in either Td, or dT/dt max. In the presence of a standard concentration of dipyridamole (26.4 mumol l-1), L-PIA produced a significant and concentration-dependent increase in both Td and dT/dt max. In the presence of a standard concentration of aminophylline (640 mumol l-1), L-PIA produced a small and insignificant, but concentration-dependent decrease of both Td and dT/dt max. In the presence of both dipyridamole (26.4 mumol l-1) and of aminophylline (640 mumol l-1), L-PIA (0.07-5.5 mumol l-1) produced a small and insignificant potentiation of the isometric contraction of the isolated hemidiaphragm. It is concluded that antagonistic action between L-PIA and aminophylline probably takes place at A1-receptors. The inhibitory action of L-PIA, observed after blockade of adenosine receptors by aminophylline, is presumably realized through some other mechanism(s) independent of adenosine receptor sites.

摘要

在直接电刺激期间，研究了L-N6-苯基异丙基腺苷（L-PIA）对大鼠离体半膈肌最大张力（Td）和最大张力上升速率（dT/dt max）的影响。L-PIA本身（0.07 - 5.5 μmol l-1）对Td或dT/dt max均未产生显著变化。在存在标准浓度双嘧达莫（26.4 μmol l-1）的情况下，L-PIA使Td和dT/dt max均显著且呈浓度依赖性增加。在存在标准浓度氨茶碱（640 μmol l-1）的情况下，L-PIA使Td和dT/dt max均出现微小且不显著但呈浓度依赖性的降低。在同时存在双嘧达莫（26.4 μmol l-1）和氨茶碱（640 μmol l-1）的情况下，L-PIA（0.07 - 5.5 μmol l-1）使离体半膈肌的等长收缩出现微小且不显著的增强。得出结论，L-PIA与氨茶碱之间的拮抗作用可能发生在A1受体处。在氨茶碱阻断腺苷受体后观察到的L-PIA的抑制作用，可能是通过一些独立于腺苷受体位点的其他机制实现的。