Arletti R, Benelli A, Bertolini A
Institute of Pharmacology, University of Modena, Italy.
Physiol Behav. 1990 Dec;48(6):825-30. doi: 10.1016/0031-9384(90)90234-u.
Increasing evidence indirectly suggests a role for oxytocinergic neurons in the control of ingestive behaviors. The present study was aimed at directly investigating a possible effect of oxytocin on food and water intake in rats. Oxytocin, whether administered intracerebroventricularly (ICV) (1-10 micrograms/rat) or intraperitoneally (IP) (375-3,000 micrograms/kg) dose dependently inhibited food intake in freely feeding animals; in schedule-fed animals fasting for 21 h, oxytocin not only reduced food intake but also reduced the time spent eating and increased the latency to first meal. On the other hand, oxytocin antagonist d(CH2)5Tyr(Me)-[Orn8]-vasotocin, ICV injected at the dose of 10 micrograms/rat, increased food intake and time spent eating and reduced the latency to first meal; moreover, it completely prevented the effect of oxytocin. Water intake was studied both in freely drinking animals and in three different models of thirst (water deprivation, hypertonic saline administration, angiotensin II injection). In all cases, oxytocin dose dependently inhibited water intake, in a dose range of 0.1-10 micrograms/rat (ICV) or 93-750 micrograms/kg (IP). In the water deprivation model, ICV pretreatment with d(CH2)5Tyr(Me)-[Orn8]-vasotocin completely prevented the antidipsogenic effect of oxytocin. In conclusion, these data show that oxytocin directly inhibits food and water intake in rats, the effect being specifically mediated by brain oxytocin receptors. This may support the idea that the brain oxytocinergic system plays an important role in the regulation of ingestive behaviors.
越来越多的证据间接表明，催产素能神经元在控制摄食行为中发挥作用。本研究旨在直接探究催产素对大鼠食物和水摄入量的可能影响。催产素，无论是脑室内注射（ICV）（1 - 10微克/只大鼠）还是腹腔注射（IP）（375 - 3000微克/千克），均能剂量依赖性地抑制自由进食动物的食物摄入量；在定时喂食且禁食21小时的动物中，催产素不仅减少了食物摄入量，还缩短了进食时间，并延长了首次进食的潜伏期。另一方面，催产素拮抗剂d(CH2)5Tyr(Me)-[Orn8]-血管催产素，以10微克/只大鼠的剂量脑室内注射，增加了食物摄入量和进食时间，并缩短了首次进食的潜伏期；此外，它完全阻断了催产素的作用。在自由饮水的动物以及三种不同的口渴模型（禁水、高渗盐水注射、血管紧张素II注射）中研究了水的摄入量。在所有情况下，催产素在0.1 - 10微克/只大鼠（ICV）或93 - 750微克/千克（IP）的剂量范围内剂量依赖性地抑制水的摄入量。在禁水模型中，用d(CH2)5Tyr(Me)-[Orn8]-血管催产素进行脑室内预处理可完全阻断催产素的抗利尿作用。总之，这些数据表明，催产素直接抑制大鼠的食物和水摄入量，该作用由脑内催产素受体特异性介导。这可能支持了脑催产素能系统在调节摄食行为中起重要作用的观点。
