A population of non-luteinising hormone/non-adrenocorticotrophic hormone-positive cells in the male rat anterior pituitary responds mitotically to both gonadectomy and adrenalectomy
A population of non-luteinising hormone/non-adrenocorticotrophic hormone-positive cells in the male rat anterior pituitary responds mitotically to both gonadectomy and adrenalectomy
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DOI：
10.1111/j.1365-2826.2006.01459.x
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发表时间：
2006-09-01
影响因子：
3.2
通讯作者：
Levy, A.
中科院分区：
文献类型：
--
作者：
Nolan, L. A.;Levy, A.
雄性大鼠垂体前叶对特定激素刺激的反应在有丝分裂和凋亡(营养)活动的范围和时间方面具有很高的重复性。本研究的主要目的是确定激素可识别细胞对双侧性腺切除和双侧肾上腺切除的营养反应的贡献。摘除肾上腺和摘除性腺的垂体有丝分裂反应在幅度和持续时间上是相似的。当切除肾上腺和性腺时，垂体有丝分裂反应的幅度不变。也就是说，营养刺激不是相加的。地塞米松诱导的新生细胞凋亡不仅在最近的肾上腺切除术中被放大，而且在几乎相同的程度上，被性腺切除术放大。联合切除肾上腺和性腺并不会进一步增加对细胞凋亡有反应的细胞群的大小。双溴脱氧尿核苷和促肾上腺皮质激素(ACTH)或促黄体生成素(LH)免疫标记显示，在有丝分裂反应高峰期，超过95%的分裂细胞不表达这两种激素中的任何一种。肾上腺切除后，大多数新形成的ACTH细胞来自于先前存在的激素未分化细胞的分化。尽管有丝分裂活性总体上有所增加，但性腺切除后促黄体生成素免疫阳性细胞的数量并没有明显增加。对肾上腺切除和性腺切除的非相加的垂体有丝分裂和凋亡反应强烈地表明，相同的祖细胞群体对两者都有有丝分裂反应。这削弱了普遍的观点，即具有特定营养特征的激素可识别细胞对垂体细胞亚群的修订有重要贡献。
The male rat anterior pituitary responds highly reproducibly to specific hormonal stimuli in terms of the extent and timing of mitotic and apoptotic (trophic) activity. The principal objective of the present study was to define the contribution of hormonally identifiable cells to the trophic responses to bilateral gonadectomy and bilateral adrenalectomy. The patterns of pituitary mitotic responses to adrenalectomy and gonadectomy are similar in amplitude and duration. When adrenalectomy and gonadectomy are combined, the amplitude of the pituitary mitotic response is unchanged. That is, the trophic stimuli are not additive. Dexamethasone-induced apoptosis in nascent cells is amplified not only by recent adrenalectomy, but also, and to an almost identical extent, by gonadectomy. Combining adrenalectomy and gonadectomy does not further enhance the size of the apoptotically-responsive cell population. Dual bromodeoxyuridine and adrenocorticotrophic hormone (ACTH) or luteinising hormone (LH) immunolabelling showed that more than 95% of all dividing cells are not and do not become positive for either of these hormones during the period of peak mitotic response. Following adrenalectomy, most newly-formed ACTH cells are derived from differentiation of pre-existing hormonally undifferentiated cells. Despite an overall increase in mitotic activity, there is no measurable increase in the number of LH immunopositive cells after gonadectomy. The nonadditive pituitary mitotic and apoptotic responses to adrenalectomy and gonadectomy strongly suggest that the same progenitor cell population responds mitotically to both. This weakens the prevailing view that hormonally identifiable cells with specific trophic profiles contribute significantly to pituitary cell subpopulation revision.