Endogenous GABA receptor ligands in hypophysial portal blood.
Endogenous GABA receptor ligands in hypophysial portal blood.
复制标题
垂体门静脉血中的内源性 GABA 受体配体。
作者：
R. Mitchell;G. Grieve;R. Dow;G. Fink
采用放射受体分析法测定垂体门静脉血浆中内源性γ-氨基丁酸（GABA）受体配体的浓度。门静脉血浆中含有较高浓度的GABA受体配体比外周对照，虽然这种增加是由于真实的GABA，但未知的低亲和力配体。证据支持的假设，二肽homocarnosine可能代表至少一部分，这是未知的。电刺激正中隆起诱发大量（7.8倍）增加释放率的GABA（但不是低亲和力成分）进入门静脉血。这些结果表明，GABA和其他可能的低亲和力配体，如高肌肽可以作为参与垂体前叶功能的中枢控制的因素。
The concentrations of endogenous gamma-aminobutyric acid (GABA) receptor ligands were measured in hypophysial portal plasma by a sensitive and specific radioreceptor assay. Portal plasma contained higher concentrations of GABA receptor ligands than peripheral controls, although this increase was not due to authentic GABA but an unknown low-affinity ligand. Evidence is presented to support the hypothesis that the dipeptide homocarnosine may represent at least a part of this unknown. Electrical stimulation of median eminence evoked a massive (7.8-fold) increase in the rate of release of GABA (but not the low-affinity component) into portal blood. These results suggest that GABA and possibly other low-affinity ligands such as homocarnosine could serve as factors involved in the central control of anterior pituitary function.