Youngren O, Chaiseha Y, Phillips R, El Halawani M
Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, Minnesota, 55108, USA.
Gen Comp Endocrinol. 1996 Sep;103(3):323-30. doi: 10.1006/gcen.1996.0128.
Hypophysial portal blood was collected for the first time in an avian species using a dorsal approach through the third ventricle and median eminence of the turkey. This was done to test for the presence of the prolactin (PRL)-releasing factor vasoactive intestinal peptide (VIP) in the portal blood and to determine whether VIP concentrations there varied with and corresponded to plasma PRL levels across the reproductive cycle. VIP concentrations in hypophysial portal blood were 2.5- to 13.5-fold greater than in the general circulation. VIP concentrations were lowest in portal blood of nonphotostimulated, reproductively inactive hens (231.8 +/- 26.4 pg/ml) and highest in incubating hens (1108.1 +/- 363.7 pg/ml), while laying, and photorefractory hens were intermediate at 372.5 +/- 95.6 and 715.3 +/- 338.5 pg/ml, respectively. These differences in concentration of VIP in portal blood mirrored those of PRL in the general circulation and support other evidence that VIP is the avian PRL-releasing factor.
首次采用经火鸡第三脑室和正中隆起的背侧入路，在鸟类中采集垂体门脉血。这样做是为了检测垂体门脉血中催乳素（PRL）释放因子血管活性肠肽（VIP）的存在，并确定那里的VIP浓度是否在整个生殖周期中随血浆PRL水平变化并与之对应。垂体门脉血中的VIP浓度比体循环中的高2.5至13.5倍。在未受光刺激、生殖不活跃的母鸡的门脉血中，VIP浓度最低（231.8±26.4 pg/ml），在正在孵蛋的母鸡中最高（1108.1±363.7 pg/ml），而产蛋母鸡和光不应期母鸡的VIP浓度处于中间水平，分别为372.5±95.6和715.3±338.5 pg/ml。门脉血中VIP浓度的这些差异与体循环中PRL的差异相似，并支持了其他证据，即VIP是鸟类PRL释放因子。
