Histological evaluation of the dopaminergic regulation of proopiomelanocortin gene expression in the intermediate lobe of the rat pituitary, involving in situ hybridization and [3H]thymidine uptake measurement.
Histological evaluation of the dopaminergic regulation of proopiomelanocortin gene expression in the intermediate lobe of the rat pituitary, involving in situ hybridization and [3H]thymidine uptake measurement.
复制标题
对大鼠垂体中叶阿黑皮质素原基因表达的多巴胺能调节进行组织学评估，包括原位杂交和[3H]胸苷摄取测量。
作者：
B. Chronwall;W. Millington;W. Griffin;J. R. Unnerstall;T. O'Donohue
黑素细胞是一种具有卵圆形光滑核的多面体分泌细胞，是大鼠垂体中间叶 (IL) 的主要细胞类型。黑素细胞并不统一，但其细胞质的着色特性有所不同。一些细胞显得明显更暗，另一些则更浅，还发现细胞染色呈中间色调。此外，使用阿片黑皮质素原（POMC）探针进行的原位杂交显示，黑色素细胞中 POMC mRNA 的分布不均匀，表明不同的细胞保持不同水平的生物合成活性。已知可改变 IL 中 POMC 相关肽分泌的多巴胺能药物会产生组织学染色特性和每个细胞 POMC mRNA 量的平行变化（通过原位杂交测定）。急性溴隐亭治疗（6 小时）使黑素细胞细胞质中的颗粒计数急剧减少（至对照水平的 10%）。长期治疗后，类似的减少仍然存在。单次注射氟哌啶醇后 6 小时，颗粒数为对照水平的 180%。长期氟哌啶醇治疗后，它们进一步升高至对照水平的300%。长期溴隐亭和氟哌啶醇治疗也改变了 IL 的厚度。溴隐亭减少和氟哌啶醇处理通过改变细胞增殖率增加了 IL 中的细胞层数。因此，氟哌啶醇治疗显着增加了[3H]胸苷标记的黑素细胞数量，而溴隐亭治疗则显着减少了[3H]胸苷标记的黑素细胞数量。有丝分裂指数也遵循相同的趋势。这些结果表明多巴胺对 IL 的调节通过两种不同的机制发挥作用：POMC 基因表达和细胞增殖。 POMC基因表达的变化是细胞的第一个快速反应。对细胞周期的影响出现在亚慢性和慢性治疗后。
The melanotroph, a polyhedral secretory cell with an ovoid smooth nucleus, is the primary cell type of the intermediate lobe (IL) of the rat pituitary. The melanotrophs are not uniform, but differ in the tinctorial properties of their cytoplasm; some cells appear distinctly darker, others lighter, and cells staining in intermediate shades are also found. In addition, in situ hybridization using proopiomelanocortin (POMC) probes shows an uneven distribution of POMC mRNA among melanotrophs, indicating that different cells maintain different levels of biosynthetic activity. Dopaminergic drugs known to alter the secretion of POMC-related peptides from the IL produced parallel changes in histological staining properties and the amount of POMC mRNA per cell, as determined by in situ hybridization. Acute bromocriptine treatment (6 h) produced a dramatic reduction in grain counts over melanotroph cytoplasm (to 10% of the control levels). A similar reduction persisted after chronic treatment. Six hours after a single haloperidol injection, the grain counts were 180% of control levels. After chronic haloperidol treatment, they were further elevated to 300% of control levels. Chronic bromocriptine and haloperidol treatment also changed the thickness of the IL. Bromocriptine reduced and haloperidol treatment increased the number of cell layers in the IL by changing the rate of cell proliferation. Thus, haloperidol treatment significantly increased and bromocriptine treatment significantly decreased the number of melanotrophs labeled by [3H]thymidine. The mitotic index followed the same trend. These results suggest that dopamine regulation of the IL acts by two different mechanisms: POMC gene expression and cellular proliferation. The change in POMC gene expression is the cell's first rapid response. The influence on the cell cycle appears after subchronic and chronic treatment.
原位杂交组织化学：一种研究单细胞基因表达的技术。
DOI：
10.1089/dna.1983.2.157
发表时间：
1983
期刊：
DNA (Mary Ann Liebert, Inc.)
影响因子：
--
作者：
Gee,CE;Roberts,JL
通讯作者：
Roberts,JL
协调调节大鼠垂体中叶的肽乙酰转移酶活性和阿片黑皮质素原基因表达。
影响因子：
4.8
作者：
Millington,WR;O'Donohue,TL;Chappell,MC;Roberts,JL;Mueller,GP
通讯作者：
Mueller,GP