The Experimental Study On The Pathogenesis Of Pituitary Prolactin-Producing Tumor

The pituitary prolactin-producing tumor ( prolactinoma ) is one of the fairly common lesions in endocrine system. Most patients with pituitary prolactinoma present with amenorrhea and galactorrhea. Other clinical menifestations, such as visual disturbances, headache, cranial nerve injury, and endocrine dysfunction, may caused by oppression of macroprolactinoma on the anterior pituitary or the hypothalamus and hyperprolactinemia. However, the pathogenesis of prolactinoma is not very clear at present. In order to elucidate the mechanisms of pituitary prolactin-producing tumors formation, three parts of studies were included in this paper: 1. Demonstrating the possibility that pituitary prolactinoma induced by E₂ in SD rats may originate from the pituitary level, independently of the influences of hypothalamic factors. Male SD rats (30 days old ) were transplanted with an extra pituitary under their renal capsules and treated with s.c. implantation of an empty or E₂( 17-β-estradiol )-laden silastic capsule. After treatment with E₂ for 60 days and 120 days, the changes at the levels of the whole body, anterior pituitary tissue and cellular ultrastructure were analysized by radioimmunoassay ( RIA), light and electron microscopy, etc. 2. Testing the effects of E₂, epidermal growth factor ( EGF) and transforming growth factor β1( TGFβ1) on the proliferative activity and PRL gene expression in primary cultured anterior pituitary cells, and the effects of E₂ on the expression of TGFα, TGFβ1 in in vitro and in vivo. Northern blot assay, in situ hybridization and laser scanning confocal microscopy( LSCM ) were employed. 3. Mutation screening in the 5' flanking sequence of the PRL gene and detecting the function of the mutant, by porymerase chain reaction ( PCR )- single-strand conformation polymorphism( SSCP ), DNA sequencing techniques and PRL promoter-luciferase fusion gene transient transfection...