Ramesh R, Proudman J A, Kuenzel W J
Department of Poultry Science, University of Maryland, College Park 20742, USA.
Gen Comp Endocrinol. 1996 Oct;104(1):67-75. doi: 10.1006/gcen.1996.0142.
Turkey hens can rapidly shift from a laying condition to one characterized by ovarian regression, incubation behavior, and hyperprolactinemia. Although remarkable changes occur in hormonal profiles as turkey hens pass from a laying to an incubating state, studies have not been undertaken to examine histochemical alterations of functionally relevant pituicytes in the adenohypophysis. The objective of this study was to compare the immunocytochemical changes in pituitary lactotrophs and somatotrophs in incubating turkey hens with those of egg laying hens. Based upon nest visiting and egg production records, laying and incubating hens were selected for sampling blood, pituitaries, and ovaries. Plasma prolactin (PRL) and growth hormone (GH) concentrations were determined. Sagittal pituitary sections of laying and incubating hens were immunostained using antibodies against turkey growth hormone or synthetic chicken PRL peptide. Somatotrophs were found predominantly in the caudal lobe while lactotrophs occurred only in the cephalic lobe of adenohypophysis in laying hens. In incubating hens, somatotrophs in the ventral half of the caudal lobe were replaced by lactotrophs. The sagittal area which immunostained for PRL was significantly greater while the area that immunostained for GH was less in the adenohypophysis of incubating turkey hens. Some of the lactotrophs were hypertrophied in incubating hens. The lactotrophic recruitment and hypertrophy provide a cellular basis for the hyperprolactinemia in incubating turkey hens.
火鸡母鸡能够迅速从产蛋状态转变为以卵巢退化、抱窝行为和高催乳素血症为特征的状态。尽管火鸡母鸡从产蛋状态转变为抱窝状态时激素水平会发生显著变化，但尚未开展研究来检查腺垂体中功能相关的垂体细胞的组织化学改变。本研究的目的是比较抱窝火鸡母鸡与产蛋母鸡垂体催乳素细胞和生长激素细胞的免疫细胞化学变化。根据进窝情况和产蛋记录，选择产蛋和抱窝母鸡采集血液、垂体和卵巢样本。测定血浆催乳素（PRL）和生长激素（GH）浓度。使用抗火鸡生长激素抗体或合成鸡PRL肽对产蛋和抱窝母鸡的垂体矢状切片进行免疫染色。产蛋母鸡中，生长激素细胞主要位于尾叶，而催乳素细胞仅出现在腺垂体的头叶。在抱窝母鸡中，尾叶腹侧一半的生长激素细胞被催乳素细胞取代。抱窝火鸡母鸡腺垂体中PRL免疫染色的矢状面积显著更大，而GH免疫染色的面积更小。一些催乳素细胞在抱窝母鸡中肥大。催乳素细胞的募集和肥大是抱窝火鸡母鸡高催乳素血症的细胞基础。
