Regulation of pituitary beta-endorphin secretion in aging rats: in vitro responsiveness to dopamine.
Regulation of pituitary beta-endorphin secretion in aging rats: in vitro responsiveness to dopamine.
复制标题
衰老大鼠垂体β-内啡肽分泌的调节：对多巴胺的体外反应。
DOI：
10.1016/0024-3205(95)00106-9
复制
发表时间：
1995
期刊：
影响因子：
6.1
通讯作者：
Ramirez,D
中科院分区：
文献类型：
--
作者：
Saland,LC;Samora,A;Apodaca,A;Ramirez,D
The intermediate lobe of the mammalian pituitary is highly responsive to dopamine inhibition of beta-endorphin secretion. In this study, the ability of aged (12 months) intermediate lobes to respond to dopamine was compared to that of young (6 weeks) tissue, using a short-term in vitro incubation of isolated rat neurointermediate lobes, with measurement of peptide release by radioimmunoassay. Tissue from the aged rats released greater amounts of betaendorphin peptide than amounts measured from young tissue at all time periods studied. The aged lobes were also found to be significantly more sensitive to dopamine than young glands, as measured by percent change of each group compared to respective baseline release. In comparison, incubation of tissue from young animals in which the intermediate lobe had been acutely denervated by treating rats with injections of the catecholamine neurotoxin, 6-hydroxydopamine, did not differ in responsiveness to dopamine as compared to tissue from control rats. The observations suggest that aging intermediate lobe, while being hypersecretory, is supersensitive to dopamine, perhaps as the result of gradually reduced innervation.
