【摘要】 在离体研究中发现，血管活性肠肽（ＶＩＰ）对催乳素分泌的促进作用因垂体所取自的动物模型的不同而异。本实验则以不同生理状态的大鼠为动物模型，于清醒自由活动状态下，检验ＶＩＰ的静脉注入对催乳素释放的影响。结果表明，在ＶＩＰ注入后１０ｍｉｎ时，其外周血液的浓度达到最高值（２１３２±２３３）ｎｇ／ｍｌ，并至少持续３０ｍｉｎ。在本实验的所有动物模型中，ＶＩＰ均诱导出了显著的催乳素分泌峰（Ｐ＜００５），就其提高程度而言，雄性鼠最高（１５８０４±３７０６）ｎｇ／ｍｌ，未经吸吮刺激的哺乳母鼠最低（３１０５±４４２）ｎｇ／ｍｌ，而经过吸吮刺激的哺乳母鼠则居于两者之间（９０１０±３６００）ｎｇ／ｍｌ。ＶＩＰ在不同动物模型中所表现出的这些差异，提示其作用方式和／或作用部位可能受到整个机体内分泌环境和神经刺激的整合。更多还原

【Abstract】 Our previous experiments in vitro showed that the stimulating effects of vasoactive intestinal polypeptide (VIP) on pituitary (PRL) depended on the endocrinal status of the animals. The present investigation was to determine whether the effect of VIP varied in vivo with changes of different physiological conditions. For infusion of VIP (5 μg/100 g body weight) and collection of blood sample, all the animals were cannulated with silicon tube into jugular vein 2～3 d before the experiments. The results showed that VIP concentration in blood was increased rapidly after the infusion (maximum: 21 32±2 33 ng/ml at 10 min and lasting more than 30 min). The concentration of PRL in blood of all the animals tested was increased significantly ( P <0 05) after VIP infusion. The increase rate of PRL induced by VIP was higher in male rats (158 04±37 06), but lower in the female (Diestrus: 50 42±16 44, Proestrus: 62 67±21 34) and in Suckling-depended lactating ones (Suckled 90 00±36 00 vs . Separated 31 05±4 42). The above observations suggest that the VIP action in vivo depends on the endocrinal and/or neural status of the animals.更多还原