Whitley J C, Moore C, Giraud A S, Shulkes A
University of Melbourne, Department of Surgery, Austin and Repatriation Medical Centre, Austin Campus, Heidelberg, Victoria 3084, Australia.
J Endocrinol. 2002 Nov;175(2):447-57. doi: 10.1677/joe.0.1750447.
High concentrations of a peptide related to gastrin-releasing peptide (GRP) are produced in the utero-placental unit of the human and sheep and secreted into the general circulation. This suggests an endocrine role in addition to its role as a neurotransmitter/neuromodulator. The GRP is larger than the previously described form GRP(1-27) but it is not known whether the larger form is the product of a related GRP-like gene or differences in post-translational processing. We have therefore cloned the gene for the sheep homologue of the GRP gene and determined its distribution. Only a single GRP gene was found in the sheep. This had a similar organisation to the human GRP gene with three exons and two introns. The larger form of GRP in the pregnant endometrium therefore appears to be the result of an alteration in processing of the GRP prohormone. The expression of GRP mRNA in the pregnant uterus was extraordinarily high comprising one-third of all mRNA synthesised by the pregnant endometrium. As the endometrial GRP mRNA arises solely from the glandular epithelium, the localised synthesis of GRP mRNA would be far higher. GRP mRNA was expressed in a wide variety of fetal tissues (fundus, colon, jejunum, ileum, duodenum, kidney, adrenal, lung, heart and pancreas) with a corresponding presence of GRP immunoreactivity. The expression of GRP in the fetal lung was biphasic with peaks at mid-term and near parturition but none in the adult supporting the concept of a specific developmental role of GRP in the lung.
在人类和绵羊的子宫 - 胎盘单位中会产生高浓度的一种与胃泌素释放肽（GRP）相关的肽，并分泌到全身循环中。这表明它除了作为神经递质/神经调节剂外，还具有内分泌作用。该GRP比先前描述的GRP(1 - 27)形式更大，但尚不清楚这种更大的形式是相关GRP样基因的产物，还是翻译后加工差异的结果。因此，我们克隆了GRP基因的绵羊同源基因并确定了其分布。在绵羊中仅发现了一个GRP基因。它与人类GRP基因具有相似的结构，有三个外显子和两个内含子。因此，妊娠子宫内膜中较大形式的GRP似乎是GRP前激素加工改变的结果。妊娠子宫中GRP mRNA的表达异常高，占妊娠子宫内膜合成的所有mRNA的三分之一。由于子宫内膜GRP mRNA仅来自腺上皮，GRP mRNA的局部合成会高得多。GRP mRNA在多种胎儿组织（胃底、结肠、空肠、回肠、十二指肠、肾脏、肾上腺、肺、心脏和胰腺）中表达，同时相应存在GRP免疫反应性。GRP在胎儿肺中的表达呈双相性，在中期和接近分娩时有峰值，但在成年动物中无表达，这支持了GRP在肺中具有特定发育作用的概念。
