Expression and localization of neuropeptide Y in pituitary adenoma
Ma Jing jian1, Chen Laizhao2, Sheng Xuedong 1. Department of Neurosurgery, General Hospital of Tianjin Medical University, Tianjin, He ping district, An shan Road, 154#. 300052
Objective To assess the expression and localization of neuropeptide Y (NPY) in human pituitary adenomatous cells, and to investigate the relationship between NPY expression and the various types of pituitary adenoma and specificity of NPY. Methods Adenomatous tissues were obtained from 57 patients with pituitary adenomas who underwent surgery and pathology according to their clinical diagnosis, who were admitted to the department of neurosurgery in General hopital of Tianjin Medical University from 2003 year to 2005 year. Using a highly specific anti-NPY polyclonal antibody, immunohistochemical analysis was performed on the surgically removed pituitary adenomas. Six spcimens also were examined by immuno-electron microscopy. Results NPY expression was significantly different among various pathology types of pituitary adenomas (P0.05). NPY is immunodetected in 59.65% of pituitary adenomas, 91.7% of gonadotrophic adenomas, 66.7% of GH and ACTH adenomss, respectively. 50% of null cell adenoma and plurihormonal adenoma, respectively, 25% of prolactinomas. Immuno-electron microscopy demonstrated that 4 of the 6 fresh specimens (GH adenomas 2 cases, mixed GH-PRL adenoma 1 case, PRL adenomas 2 cases and gonadotrophic adenana 1 case)displayed positive NPY staining with a high density of gold particles located mainly in the secretory granulas. In addition, gold particles were sparsely detected in the rough endoplasmic reticulum and cell matrix. A few of positive NPY secretory granulas were observated in prolacinomas. Conclusions ①The NPY expression level was significantly different among various types of pitutary adenomas. ②NPY expression was significantly higher in gonadotrophic adenomas and lower in prolactinoma.