Trejter Marcin, Neri Giuliano, Rucinski Marcin, Majchrzak Mariola, Nussdorfer Gastone G, Malendowicz Ludwik K
Department of Histology and Embryology, Poznan University of Medical Science, PL-60781 Poznan, Poland.
Int J Mol Med. 2008 Jun;21(6):683-7.
Neuromedin-U (NMU) is a brain-gut peptide, which has been previously found to stimulate hypothalamic-pituitary-adrenal axis in the rat. Enucleation-induced adrenal regeneration in rats with contralateral adrenalectomy is a well-established model of adrenal growth, that not only depends on the compensatory ACTH hypersecretion, but is also modulated by several regulatory peptides. Hence, we investigated whether NMU may be included in this group of bioactive molecules. Reverse transcription-polymerase chain reaction and immunocytochemistry showed that regenerating rat adrenocortical cells at days 5 and 8 after surgery express the NMU receptor NMUR1 as mRNA and protein. NMU8 administration to rats bearing regenerating adrenals markedly raised the plasma concentration of corticosterone and notably enhanced proliferative activity of adrenocortical cells. ACTH blood level was unchanged at day 5 and significantly decreased at day 8. The conclusion is drawn that NMU stimulates regeneration of rat adrenal cortex, via a mechanism independent of pituitary ACTH and involving the activation of NMUR1 located on adrenocortical cells.
神经介素U（NMU）是一种脑肠肽，此前已发现它能刺激大鼠的下丘脑 - 垂体 - 肾上腺轴。对侧肾上腺切除术后大鼠的眼球摘除诱导的肾上腺再生是一种成熟的肾上腺生长模型，它不仅依赖于代偿性促肾上腺皮质激素（ACTH）分泌过多，还受到多种调节肽的调节。因此，我们研究了NMU是否可能属于这组生物活性分子。逆转录 - 聚合酶链反应和免疫细胞化学显示，术后第5天和第8天再生的大鼠肾上腺皮质细胞以mRNA和蛋白质形式表达NMU受体NMUR1。给肾上腺再生的大鼠注射NMU8可显著提高血浆皮质酮浓度，并显著增强肾上腺皮质细胞的增殖活性。第5天促肾上腺皮质激素血液水平未改变，第8天显著降低。得出的结论是，NMU通过独立于垂体ACTH且涉及肾上腺皮质细胞上NMUR1激活的机制刺激大鼠肾上腺皮质再生。
