Anterior pituitary cell population control: Basal cell turnover and the effects of adrenalectomy and dexamethasone treatment
Anterior pituitary cell population control: Basal cell turnover and the effects of adrenalectomy and dexamethasone treatment
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DOI：
10.1046/j.1365-2826.1998.00191.x
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发表时间：
1998-03-01
影响因子：
3.2
通讯作者：
Levy, A
中科院分区：
文献类型：
--
作者：
Nolan, LA;Kavanagh, E;Levy, A
我们使用了一种非常准确的、专用的、实时的计算机图像分析系统，以便于手动量化手术切除肾上腺和14天后接受地塞米松治疗的雄性大鼠垂体中有丝分裂图形和凋亡小体的变化。基础状态下，核分裂像和凋亡小体的发生率分别为0.066+/-0.016%和0.030+/-0.012%(平均值+/-SE)。地塞米松治疗降低了有丝分裂的发生率，并在肾上腺切除动物中产生了非常显著和可重复性的细胞凋亡活性爆发，在治疗开始后48小时达到高峰(0.261+/-0.022%)，然后在进一步的8小时内急剧下降到对照水平。秋水仙碱处理后体内有丝分裂图形的积累速度表明，光镜下2微米厚的苏木精-伊红染色切片在组织学上可见有丝分裂，经鉴定为典型的凋亡体的凋亡可持续44min，平均而言，幼年、成年、雄性大鼠的垂体前叶细胞死亡或分裂频率高达每60-70天一次。这些数据表明，凋亡和有丝分裂事件发生率的短暂和表面上的微小波动对垂体细胞种群动态有深远的影响，并表明地塞米松治疗肾上腺切除大鼠后，垂体前叶细胞总数下降，并在开始糖皮质激素治疗后至少持续2周。
We have used an extremely accurate, dedicated, real time computerized image analysis system to facilitate the manual quantification of changes in the prevalence of mitotic figures and apoptotic bodies in male rat pituitary following surgical adrenalectomy and, 14 days later, dexamethasone treatment. Under basal conditions, the prevalence of mitotic figures and apoptotic bodies was 0.066 +/- 0.016% and 0.030 +/- 0.012% (mean +/- SE) respectively. Dexamethasone treatment reduced the prevalence of mitotic figures and, in adrenalectomized animals, produced a highly significant and reproducible burst of apoptotic activity that peaked 48 h after the beginning of treatment (0.261 +/- 0.022%) before falling sharply to control levels within a further 8 h. Two weeks after the start of dexamethasone treatment, total pituitary cell numbers continued to decline. The rate of accumulation of mitotic figures in vivo after colchicine treatment indicates that mitosis is histologically overt in 2 mu m thick hematoxylin and eosin stained sections under the light microscope for around 80 min; that apoptosis-identified as classical apoptotic bodies-is overt for 44 min and that, on average, a young, adult, male rat anterior pituitary cell either dies or divides as frequently as once every 60-70 days. These data show that transient and apparently trivial fluctuations in the prevalence of apoptotic and mitotic events have a profound effect on pituitary cell population dynamics, and demonstrate that dexamethasone treatment of adrenalectomized rats produces a decline in total anterior pituitary cell numbers that continues for at least 2 weeks after the start of glucocorticoid treatment.