Rökaeus A, Burcher E, Chang D, Folkers K, Rosell S
Acta Pharmacol Toxicol (Copenh). 1977 Aug;41(2):141-7. doi: 10.1111/j.1600-0773.1977.tb02134.x.
The actions of neurotensin and (Gln4)-neurotensin have been investigated on a number of isolated tissues. They were ineffective in contracting the guinea pig vas deferens, the rabbit aortic strip or the frog rectus abdominis muscle in concentrations up to 0.24 micron. Neurotensin and (Gln4)-neurotensin relaxed the rat duodenum at fairly high concentrations (24 nM). The guinea pig ileum contracted in response to increasing doses, although the maximum response were only one half that caused by histamine. Tachyphylaxis was observed at dose intervals of less than 12 minutes, but this tachyphylaxis did not inhibit responses to acetylcholine, histamine, 5-HT or to DMPP, suggesting that the neurotensins may act at specific receptor sites. They contracted the rat fundus strip at concentrations of 0.24 nM and higher. The neurotensins and 5-HT were approximately equipotent on this tissue, although the maximum responses was about 80% of that to 5-HT. The contractions of the rat fundus strip could not be blocked by atropine, hexamethonium, methysergide, morphine or by 7-OH-THC. These data indicate that neurotensin and (Gln4)-neurotensin are equipotent as far as smooth muscle stimulating activity is concerned. Of those organs tested, the rat fundus strip seems to be the most suitable one for studies concerning structure-activity relationships.
已经在多种离体组织上研究了神经降压素和（Gln4）-神经降压素的作用。在浓度高达0.24微摩尔时，它们对豚鼠输精管、兔主动脉条或青蛙腹直肌的收缩无效。神经降压素和（Gln4）-神经降压素在相当高的浓度（24纳摩尔）时可使大鼠十二指肠松弛。豚鼠回肠对剂量增加有收缩反应，尽管最大反应仅为组胺引起反应的一半。在剂量间隔小于12分钟时观察到快速耐受性，但这种快速耐受性并不抑制对乙酰胆碱、组胺、5-羟色胺或二甲基苯基哌嗪的反应，这表明神经降压素可能作用于特定的受体部位。它们在浓度为0.24纳摩尔及更高时可使大鼠胃底条收缩。神经降压素和5-羟色胺在该组织上的效力大致相当，尽管最大反应约为5-羟色胺反应的80%。大鼠胃底条的收缩不能被阿托品、六甲铵、麦角新碱、吗啡或7-羟基-四氢大麻酚阻断。这些数据表明，就平滑肌刺激活性而言，神经降压素和（Gln4）-神经降压素效力相当。在测试的那些器官中，大鼠胃底条似乎是研究构效关系最适合的器官。
