Christie J, Satchell D G
Br J Pharmacol. 1980 Dec;70(4):512-4. doi: 10.1111/j.1476-5381.1980.tb09768.x.
In guinea-pig trachea adenosine 5'-triphosphate (ATP), adenosine 5'-diphosphate (ADP), adenosine 5'-phosphate (AMP), adenosine and adenine were similarly potent in causing relaxation of the smooth muscle. This is in contrast to gut where ATP and ADP are 30 times more potent than adenosine. Studies with dipyridamole suggest that in trachea, as in gut, nucleotides are rapidly metabolized to adenosine. A polyphosphate modified analogue of ATP, the alpha,beta-methylene isostere, which resists degradation to adenosine was inactive in trachea although it is a potent relaxant in gut. This result may suggest that the intact ATP molecule is also inactive in the tracheal preparation: i.e. ATP acts only via its adenosine metabolite implying that receptors for adenosine but not ATP are present in the tissue.
在豚鼠气管中，5'-三磷酸腺苷（ATP）、5'-二磷酸腺苷（ADP）、5'-磷酸腺苷（AMP）、腺苷和腺嘌呤引起平滑肌舒张的效力相似。这与肠道情况相反，在肠道中ATP和ADP的效力比腺苷强30倍。双嘧达莫的研究表明，在气管中，与在肠道中一样，核苷酸会迅速代谢为腺苷。一种ATP的多磷酸盐修饰类似物，即α,β-亚甲基等排体，它能抵抗降解为腺苷，在气管中无活性，尽管它在肠道中是一种有效的舒张剂。这一结果可能表明完整的ATP分子在气管制剂中也无活性：即ATP仅通过其腺苷代谢产物起作用，这意味着该组织中存在腺苷受体而非ATP受体。
