De Luca A, Squillacioti C, Pero M E, Paino S, Langella E, Mirabella N
Department of Structures, Functions and Biological Technologies, University of Naples Federico II, Napoli, Italy.
Eur J Histochem. 2009 Sep 23;53(3):e20. doi: 10.4081/ejh.2009.e20.
Urocortin (UCN) is a 40 aminoacid peptide which belongs to corticotropin-releasing factor (CRF) family. This family of peptides stimulates the secretion of proopiomelanocortin (POMC)-derived peptides, adrenocorticotropic hormone (ACTH), beta-endorphin and melanocyte-stimulating hormone (MSH) in the pituitary gland. In the present study, using Western blotting and immunohistochemistry, the distribution of UCN in the primary lymphoid organs of the duck was investigated at different ages. In the cloacal burse and thymus, Western blot demonstrated the presence of a peptide having a molecular weight compatible with that of the mammalian UCN. In the cloacal burse, immunoreactivity was located in the medullary epithelial cells and in the follicular associated and cortico-medullary epithelium. In the thymus, immunoreactivity was located in single epithelial cells. Double labelling immunofluorescence studies showed that UCN immunoreactivity completely colocalised with cytokeratin immunoreactivity in both the thymus and cloacal burse. Statistically significant differences in the percentage of UCN immunoreactivity were observed between different age periods in the cloacal burse. The results suggest that, in birds, urocortin has an important role in regulating the function of the immune system.
尿皮质素（UCN）是一种由40个氨基酸组成的肽，属于促肾上腺皮质激素释放因子（CRF）家族。该肽家族可刺激垂体中阿片促黑皮质素原（POMC）衍生肽、促肾上腺皮质激素（ACTH）、β-内啡肽和促黑素细胞激素（MSH）的分泌。在本研究中，运用蛋白质免疫印迹法和免疫组织化学方法，对不同年龄段鸭的初级淋巴器官中UCN的分布进行了研究。在泄殖腔法氏囊和胸腺中，蛋白质免疫印迹显示存在一种分子量与哺乳动物UCN相符的肽。在泄殖腔法氏囊中，免疫反应性位于髓质上皮细胞以及滤泡相关上皮和皮质-髓质上皮中。在胸腺中，免疫反应性位于单个上皮细胞中。双标记免疫荧光研究表明，在胸腺和泄殖腔法氏囊中，UCN免疫反应性与细胞角蛋白免疫反应性完全共定位。在泄殖腔法氏囊中，不同年龄段之间UCN免疫反应性百分比存在统计学上的显著差异。结果表明，在鸟类中，尿皮质素在调节免疫系统功能方面具有重要作用。
