Chipkin R E, Stewart J M, Morris D H
Eur J Pharmacol. 1978 Dec 15;53(1):21-7. doi: 10.1016/0014-2999(78)90263-7.
In the past, substance P (SP) has been suggested to be both an opiate agonist and an antagonist. It therfore seemed appropriate to examine potential interactions of SP and opioids on guinea pig ileum. On non-stimulated ileal strips SP caused a dose responsive increase in contraction. Pretreatment of the tissue with morphine (3, 30, 300, 3000 nM), enkephalin (1.42, 14.2, 142, 1420 nM), naloxone (5nM), or atropine (0.144 micron) did not significantly alter the spasmogenic effect of SP. On stimulated guinea pig ileum, whereas morphine and enkephalin inhibited the electrically induced twitch, SP adminstration resulted in contraction of the tissue. Additionally, neither strongly effective non sub-threshold doses of SP antagonized the effects of the narcotics. These data are discussed in terms of separate receptors mediating the effects of the opiates and SP on guinea pig ileum.
过去，P物质（SP）曾被认为既是一种阿片类激动剂又是一种拮抗剂。因此，研究SP与阿片类药物在豚鼠回肠上的潜在相互作用似乎是合适的。在未受刺激的回肠条上，SP引起剂量依赖性的收缩增加。用吗啡（3、30、300、3000 nM）、脑啡肽（1.42、14.2、142、1420 nM）、纳洛酮（5 nM）或阿托品（0.144微米）对组织进行预处理，并未显著改变SP的致痉挛作用。在受刺激的豚鼠回肠上，吗啡和脑啡肽抑制电诱导的抽搐，而给予SP则导致组织收缩。此外，无论是强效的非阈下剂量的SP也不能拮抗麻醉剂的作用。本文根据介导阿片类药物和SP对豚鼠回肠作用的不同受体对这些数据进行了讨论。
