Fargeas M J, Fioramonti J, Bueno L
Department of Pharmacology INRA, Toulouse, France.
Peptides. 1990 Nov-Dec;11(6):1169-73. doi: 10.1016/0196-9781(90)90148-x.
The effects of intracerebroventricular (ICV) administration of neurotensin (NT) before a meal on intestinal postprandial motility were examined in conscious rats chronically fitted with intraparietal Nichrome electrodes in the duodeno-jejunum. The effects were compared with those of two analogues, [D-Tyr11]NT and [D-Trp11]NT, resistant to degradation by brain peptidases. NT (10 micrograms ICV) delayed the occurrence of postprandial disruption of duodenal motility and blocked it on the jejunum. [D-Tyr11]NT and [D-Trp11]NT (1 microgram ICV) elicited the same effects but at a ten-fold lower dose. NT administered peripherally just before a meal significantly lengthened the duration of the postprandial motor pattern. The central effect of NT on the fed pattern involved dopaminergic neurons as it was mimicked by dopamine, blocked by haloperidol and partly antagonized by either sulpiride or (+) SCH 23390. It is concluded that: 1) both D1 and D2 receptors are involved in the blocking effect of the postprandial disruption induced by central NT; 2) that [D-Tyr11]NT and [D-Trp11]NT are potent agonists at NT receptors in the brain.
在长期植入十二指肠 - 空肠内镍铬合金电极的清醒大鼠中，研究了餐前脑室内（ICV）注射神经降压素（NT）对肠道餐后运动的影响。并将这些影响与两种对脑肽酶降解具有抗性的类似物[D - Tyr11]NT和[D - Trp11]NT的影响进行了比较。NT（10微克ICV）延迟了十二指肠运动餐后紊乱的发生，并阻止了空肠的紊乱。[D - Tyr11]NT和[D - Trp11]NT（1微克ICV）产生相同的效果，但剂量低十倍。餐前外周给予NT显著延长了餐后运动模式的持续时间。NT对进食模式的中枢作用涉及多巴胺能神经元，因为多巴胺可模拟该作用，氟哌啶醇可阻断该作用，而舒必利或（+）SCH 23390可部分拮抗该作用。得出以下结论：1）D1和D2受体均参与中枢NT诱导的餐后紊乱的阻断作用；2）[D - Tyr11]NT和[D - Trp11]NT是脑内NT受体的强效激动剂。
