In pigs, plasma prolactin concentration markedly changes during the oestrous cycle and the regulation of its secretion is very complex. The contribution of neurokinins in this process has not been sufficiently delineated. The aim of the study was to examine the effects of neurokinin A (NKA) on prolactin synthesis and secretion in cyclic gilts. The expression of NKA precursor (Ppta) and receptor (Tacr2) genes as well as NKA and TACR proteins content in the porcine pituitaries (days 2-3, 9-10, 12-13, 15-16 and 19-20 of the cycle) was determined. Furthermore, the in vitro influence of NKA on the expression of prolactin (Prl), dopamine receptor (D2r), TRH receptor (Trhr) genes and prolactin secretion by the porcine pituitary cells (days 9-10, 15-16 and 19-20 of the cycle) was assessed. The expression of Ppta and Tacr2 as well as NKA and TACR proteins in the pituitary tissue has been changing throughout the oestrous cycle. NKA affected in vitro the expression of studied genes and prolactin secretion depending on the stage of the cycle, dose of NKA and/or duration of the cell incubation. Altogether, the study indicates that NKA is engaged in the modulation of prolactin secretion in the pig during the oestrous cycle.

中文翻译：

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神经激肽A及其受体在循环猪垂体前叶调节催乳素分泌中的作用。

在猪中，血浆催乳素的浓度在发情周期中发生明显变化，其分泌调节非常复杂。在此过程中神经激肽的作用尚未得到充分描述。这项研究的目的是检查神经激肽A（NKA）对周期母猪泌乳素合成和分泌的影响。猪垂体（周期的2-3、9-10、12-13、15-16和19-20天）中NKA前体（Ppta）和受体（Tacr2）基因的表达以及NKA和TACR蛋白的含量）已确定。此外，NKA对猪垂体细胞泌乳素（Pr1），多巴胺受体（D2r），TRH受体（Trhr）基因和泌乳素分泌的体外影响（第9-10、15-16和19-20天）周期）。垂体组织中Ppta和Tacr2以及NKA和TACR蛋白的表达一直在变化。NKA在体外影响研究基因的表达和催乳激素分泌，这取决于周期的阶段，NKA的剂量和/或细胞孵育的持续时间。总而言之，该研究表明NKA在发情周期中参与了猪催乳素分泌的调节。