Hayashi E, Maeda T, Shinozuka K
Br J Pharmacol. 1985 Mar;84(3):765-71. doi: 10.1111/j.1476-5381.1985.tb16159.x.
The action of adenosine on the myenteric plexus-longitudinal muscle strips from guinea-pig ileum to high frequency electrical field stimulation (10 Hz) was investigated. Electrically induced contractions were reduced markedly by tetrodotoxin (0.2 microM) and atropine (1 microM), and partially by noradrenaline (3 microM) and morphine (3 microM). Adenosine, adenosine 5'-monophosphate (AMP) and adenosine triphosphate (ATP) produced a concentration-dependent inhibition of the high frequency contractions over the range of 0.1-100 microM, the most potent being adenosine. The concentration-response curve for adenosine was significantly shifted to the left by dipyridamole (10 nM), while dipyridamole at higher concentrations (30 nM-10 microM), depressed the contraction markedly by itself. Dipyridamole decreased [3H]-adenosine uptake into strips of ileum in a concentration-dependent manner. There was a significant correlationship between the reduction of adenosine uptake and the inhibition of the contraction induced by dipyridamole (r = 0.970). In strips desensitized to adenosine or treated with adenosine deaminase, the inhibitory effect of dipyridamole was significantly reduced. The present investigation revealed that adenosine depressed responses of guinea-pig ileum to high frequency electrical stimulation and suggested that the inhibitory effect of dipyridamole may be closely associated with the behaviour of endogenous adenosine or related compounds.
研究了腺苷对豚鼠回肠肌间神经丛 - 纵行肌条对高频电场刺激（10Hz）的作用。河豚毒素（0.2微摩尔）和阿托品（1微摩尔）可显著降低电诱导的收缩，去甲肾上腺素（3微摩尔）和吗啡（3微摩尔）则部分降低收缩。腺苷、腺苷5'-单磷酸（AMP）和三磷酸腺苷（ATP）在0.1 - 100微摩尔范围内对高频收缩产生浓度依赖性抑制，其中腺苷作用最强。双嘧达莫（10纳摩尔）可使腺苷的浓度 - 反应曲线显著左移，而较高浓度（30纳摩尔 - 10微摩尔）的双嘧达莫自身可显著抑制收缩。双嘧达莫以浓度依赖性方式降低[3H] - 腺苷进入回肠肌条的摄取。腺苷摄取减少与双嘧达莫诱导的收缩抑制之间存在显著相关性（r = 0.970）。在对腺苷脱敏或用腺苷脱氨酶处理的肌条中，双嘧达莫的抑制作用显著降低。本研究表明，腺苷可抑制豚鼠回肠对高频电刺激的反应，并提示双嘧达莫的抑制作用可能与内源性腺苷或相关化合物的行为密切相关。
