Pisera D, De Laurentiis A, Duvilanski B, Lasaga M, Díaz M C, Seilicovich A
Centro de Investigaciones en Reproducción, Facultad de Medicina, Universidad de Buenos Aires, Argentina.
Neuroreport. 1996 Sep 2;7(13):2236-40. doi: 10.1097/00001756-199609020-00035.
We have studied the in vitro effects of neurokinin A (NKA) on anterior pituitary GABA concentration and GABA release from the mediobasal hypothalamus and the neurointermediate lobe of male and ovariectomized female (OVX) rats. NKA significantly decreased the anterior pituitary GABA concentration, while the presence of a specific anti-NKA serum in the incubation medium increased the GABA concentration in this gland. By contrast, NKA did not modify basal or K(+)-evoked GABA release from the mediobasal hypothalamus of male or OVX rats. However, NKA decreased basal and K(+)-evoked GABA release from the neurointermediate lobe. Since GABA inhibits both prolactin (PRL) secretion from the anterior pituitary and the release of several putative PRL-releasing factors from the neurointermediate lobe, the decrease in anterior pituitary GABA concentration and the reduction in tubero-hypophyseal GABAergic activity induced by NKA may contribute to the stimulatory effect of this peptide on PRL secretion.
我们研究了神经激肽A（NKA）对雄性和去卵巢雌性（OVX）大鼠垂体前叶GABA浓度以及来自中基底部下丘脑和神经中间叶的GABA释放的体外作用。NKA显著降低了垂体前叶的GABA浓度，而在孵育培养基中加入特异性抗NKA血清则增加了该腺体中的GABA浓度。相比之下，NKA并未改变雄性或OVX大鼠中基底部下丘脑的基础或K⁺诱发的GABA释放。然而，NKA降低了神经中间叶的基础和K⁺诱发的GABA释放。由于GABA既抑制垂体前叶催乳素（PRL）的分泌，又抑制神经中间叶几种假定的PRL释放因子的释放，NKA诱导的垂体前叶GABA浓度降低和结节 - 垂体GABA能活性降低可能有助于该肽对PRL分泌的刺激作用。
