O'Halloran D J, Jones P M, Steel J H, Gon G, Giaid A, Ghatei M A, Polak J M, Bloom S R
Department of Medicine, Royal Postgraduate Medical School, Hammersmith Hospital, London, United Kingdom.
Endocrinology. 1990 Jul;127(1):467-75. doi: 10.1210/endo-127-1-467.
Galanin is widely distributed throughout the rat neural and endocrine system. The highest concentrations are found in the anterior pituitary, and it can influence classical pituitary hormone secretion. The effects of endocrine manipulation on pituitary galanin content, mRNA, and immunostaining have been investigated in the rat. In females, medical (39 +/- 4 fmol/gland), surgical (33 +/- 2), or combined (28 +/- 6) castration resulted in a highly significant decrease in galanin content (control, 223 +/- 14; P less than 0.0001). Estrogen in physiological and pharmacological doses produced a significant increase in galanin content (368 +/- 14 and 373 +/- 13, respectively; P less than 0.01) associated with an increase in galanin mRNA content. In the male, high dose dexamethasone and thyroidectomy caused a fall in galanin content, while galanin mRNA levels showed a rise and fall, respectively. Adrenalectomy caused a rise in galanin content, while adrenalectomy and castration produced a dramatic decrease in tissue galanin content. No change in galanin mRNA was observed in these groups. Galanin immunostaining paralleled the results of tissue content in all groups examined, except in the medically castrated group, in which there was some intragroup variation in staining patterns. In normal and high-dose estrogen-treated females, galanin expression was seen mainly in lactotrophs, with a small number of somatotrophs and thyrotrophs staining. In the male, galanin expression was confined to somatotrophs and thyrotrophs. Galanin mRNA was localized at the cellular level by in situ hybridization. In the normal pituitary only scattered lactotrophs contained message, while in high-dose estrogen-treated animals the number of positive cells, mostly lactotrophs, was vastly increased. Thus, the cellular localization of galanin immunostaining varies between the sexes. Galanin peptide and mRNA levels in the pituitary are powerfully influenced by endocrine status.
甘丙肽广泛分布于大鼠的神经和内分泌系统。其最高浓度见于垂体前叶，并且它能够影响经典垂体激素的分泌。在大鼠中，已经研究了内分泌调控对垂体甘丙肽含量、信使核糖核酸（mRNA）及免疫染色的影响。在雌性大鼠中，药物性去势（39±4飞摩尔/腺体）、手术去势（33±2）或联合去势（28±6）均导致甘丙肽含量显著降低（对照组为223±14；P＜0.0001）。生理剂量和药理剂量的雌激素均使甘丙肽含量显著增加（分别为368±14和373±13；P＜0.01），同时甘丙肽mRNA含量也增加。在雄性大鼠中，高剂量地塞米松和甲状腺切除导致甘丙肽含量下降，而甘丙肽mRNA水平则分别出现升高和下降。肾上腺切除导致甘丙肽含量升高，而肾上腺切除加去势则使组织甘丙肽含量显著降低。在这些组中未观察到甘丙肽mRNA有变化。除药物性去势组外，在所有检测组中甘丙肽免疫染色结果与组织含量结果一致，在药物性去势组中染色模式存在组内差异。在正常和高剂量雌激素处理的雌性大鼠中，甘丙肽表达主要见于催乳素细胞，少数生长激素细胞和促甲状腺激素细胞染色。在雄性大鼠中，甘丙肽表达局限于生长激素细胞和促甲状腺激素细胞。通过原位杂交在细胞水平定位甘丙肽mRNA。在正常垂体中只有散在的催乳素细胞含有该信息，而在高剂量雌激素处理的动物中，阳性细胞数量大幅增加，大多数为催乳素细胞。因此，甘丙肽免疫染色的细胞定位在两性之间有所不同。垂体中的甘丙肽肽和mRNA水平受内分泌状态的强烈影响。
