Steel J H, Van Noorden S, Ballesta J, Gibson S J, Ghatei M A, Burrin J, Leonhardt U, Domin J, Bloom S R, Polak J M
Department of Histochemistry, Royal Postgraduate Medical School, Hammersmith Hospital, London, England.
Endocrinology. 1988 Jan;122(1):270-82. doi: 10.1210/endo-122-1-270.
The distributions of three novel peptides, 7B2, neuromedin B, and neuromedin U, in rat, mouse, and human pituitaries, rat hypothalamus, and 30 human pituitary tumors were investigated with immunocytochemistry. Immunoreactivity for 7B2 was present in rat, mouse, and human gonadotropes, in intermediate lobe cells and posterior lobe nerve fibers in rats and mice, in rat hypothalamus (particularly in the median eminence), and in eight human pituitary gonadotropinomas. In gonadectomized rats, larger, more numerous LH beta- and 7B2-immunoreactive gonadotropes were seen than in controls. Extractable 7B2-like immunoreactivity was elevated but not significantly so in gonadectomized rat pituitaries [males: castrated, 37.4 +/- 4.3 (mean +/- SE); controls, 26.9 +/- 4.3; females: ovariectomized, 27.2 +/- 2.7; controls, 19.1 +/- 2.2 pmol/gland]. Neuromedin B immunoreactivity was found in normal rat and mouse thyrotropes and weakly in "thyroidectomy" cells in hypothyroid rats, in which extractable pituitary neuromedin B was significantly depleted (thyroidectomized, 87.0 +/- 14.0; methimazole-treated, 82.0 +/- 11.4; control, 230.7 +/- 25.6 fmol/gland). Hyperthyroid rat pituitaries showed increased TSH beta and neuromedin B immunoreactivities and neuromedin B content (TRH-treated, 385.2 +/- 30.2; T4-treated, 352.6 +/- 20.2; control, 230.7 +/- 25.6 fmol/gland). Neuromedin U immunoreactivity occurred in corticotropes of all species, in rat and mouse intermediate lobe, and throughout the rat hypothalamus, with immunoreactive cell bodies in the arcuate nucleus. Neuromedin U-immunoreactive cells were present in six of six human pituitary and five of six human extrapituitary corticotropinomas. In adrenalectomized rats, corticotropes were larger and more numerous than in controls, but extractable anterior pituitary neuromedin U-like immunoreactivity was not raised (adrenalectomized, 3.30 +/- 0.45; control, 3.32 +/- 0.27 pmol/gland). Our findings suggest that 7B2, neuromedin B, and neuromedin U may be involved in pituitary function.
采用免疫细胞化学方法，研究了三种新型肽（7B2、神经降压素B和神经降压素U）在大鼠、小鼠和人垂体、大鼠下丘脑以及30例人垂体肿瘤中的分布。7B2的免疫反应性存在于大鼠、小鼠和人的促性腺激素细胞中，在大鼠和小鼠的中间叶细胞及后叶神经纤维中、大鼠下丘脑（特别是正中隆起）以及8例人垂体促性腺激素瘤中也有发现。在去性腺大鼠中，可见到比对照组更大、数量更多的促黄体生成素β和7B2免疫反应性促性腺激素细胞。去性腺大鼠垂体中可提取的7B2样免疫反应性升高，但无显著差异[雄性：去势，37.4±4.3（均值±标准误）；对照组，26.9±4.3；雌性：去卵巢，27.2±2.7；对照组，19.1±2.2 pmol/腺体]。神经降压素B的免疫反应性在正常大鼠和小鼠的促甲状腺激素细胞中发现，在甲状腺功能减退大鼠的“甲状腺切除”细胞中较弱，其中垂体可提取的神经降压素B显著减少（甲状腺切除，87.0±14.0；甲巯咪唑处理，82.0±11.4；对照组，230.7±25.6 fmol/腺体）。甲状腺功能亢进大鼠垂体显示促甲状腺激素β和神经降压素B免疫反应性及神经降压素B含量增加（促甲状腺激素释放激素处理，385.2±30.2；甲状腺素处理，352.6±20.2；对照组，230.7±25.6 fmol/腺体）。神经降压素U的免疫反应性存在于所有物种的促肾上腺皮质激素细胞中、大鼠和小鼠中间叶以及整个大鼠下丘脑，在弓状核中有免疫反应性细胞体。神经降压素U免疫反应性细胞存在于所有6例人垂体和其中5例人垂体外促肾上腺皮质激素瘤中。在肾上腺切除大鼠中，促肾上腺皮质激素细胞比对照组更大、数量更多，但垂体前叶可提取的神经降压素U样免疫反应性未升高（肾上腺切除，3.30±0.45；对照组，3.32±0.27 pmol/腺体）。我们的研究结果表明，7B2、神经降压素B和神经降压素U可能参与垂体功能。
