Dopaminergic regulation of glandular kallikrein in the intermediate lobe of the rat pituitary.
Dopaminergic regulation of glandular kallikrein in the intermediate lobe of the rat pituitary.
复制标题
大鼠垂体中叶腺激肽释放酶的多巴胺能调节。
DOI：
10.1159/000124564
复制
发表时间：
1986
影响因子：
4.1
通讯作者：
Powers,CA
中科院分区：
文献类型：
--
作者：
Powers,CA
大鼠脑垂体的中叶含有一种胰蛋白酶样蛋白酶，与腺激肽释放酶密切相关或相同。本研究探讨了是否腺激肽释放酶在中叶的抑制控制下的多巴胺能系统。雄性大鼠用不同剂量的以下药物单独或联合给药4-6天：氟哌啶醇（一种多巴胺受体阻滞剂）、利血平（一种儿茶酚胺消耗剂）和溴隐亭（一种多巴胺受体激动剂）。制备神经中间叶（）匀浆。在用trypin激活潜在酶后，使用两种显色肽底物测量腺激肽释放酶。氟哌啶醇使腺激肽释放酶活性加倍。解剖显示，氟哌啶醇特异性增加了中叶的腺激肽释放酶，对神经叶的少量活性没有影响。利血平也加倍腺激肽释放酶和氟哌啶醇没有产生进一步的增加。利血平诱导的腺激肽释放酶的增加被同时给予溴隐亭完全阻断：这种作用被氟哌啶醇阻断。结果表明中叶腺激肽释放酶受多巴胺能系统的抑制控制。这与中间叶中阿黑皮素原（POMC）合成的调节平行，并表明腺激肽释放酶应作为POMC加工酶进行评价。
The intermediate lobe of the rat pituitary contains a trypsin-like protease closely related or identical to glandular kallikrein. This study examined whether glandular kallikrein in the intermediate lobe is under inhibitory control by dopaminergic systems. Male rats were treated for 4–6 days with various doses of the following drugs, alone or in combination: haloperidol (a dopamine receptor blocker), reserpine (a catecholamine depleting agent), and bromocriptine (a dopamine receptor agonist). Neurointermediate lobe () homogenates were prepared. Following activation of latent enzymes with tryspin, glandular kallikrein was measured using two chromogenic peptide substrates. Haloperidol doubled glandular kallikrein activity. Dissection of the revealed that haloperidol specifically increased glandular kallikrein in the intermediate lobe and had no effect on the small amount of activity in the neural lobe. Reserpine also doubled glandular kallikrein and haloperidol did not produce further increases. The reserpine-induced increase in glandular kallikrein was completely blocked by concurrent administration of bromocriptine: this effect was blocked by haloperidol. The results demonstrate that intermediate lobe glandular kallikrein is under inhibitory control by dopaminergic systems. This parallels the regulation of proopiomelanocortin (POMC) synthesis in the intermediate lobe and suggests that glandular kallikrein should be evaluated as a POMC-processing enzyme.