Change in Heterogeneity of Pituitaly-extractd ProLactin in the Estrogen-induced Adenoma Formation in Rats

エストロゲン投与によるラット下垂体の腺腫化と産生プロラクチンの多様性の変化

Change in Heterogeneity of Pituitaly-extractd ProLactin in the Estrogen-induced Adenoma Formation in Rats

Creators Uchimichi Akihiko

Rat pituitary prolactinoma model induced by estrogen was analyzed by two-dimentinal electrophoresis to clarify change in prolactinoma-formation process. Ten week-aged female Wistar rats 150-170gm were used in this study. Long-active 17/β-estradiol (Ovahormone Depot^<[○!R]>) was injected intramusculal once a week. The animals were divided into 6groups by the number of 17β-estradiol injection. They were the group of 0 week (no-injection) (n=12), the group of 2 weeks (n=10), the group of 4 weeks (n=10), the group of 6 weeks (n=8), the group of 8 weeks (n=6), the group of 9 weeks (n=6) (total rat number N=52). Each excised pituitary gland was examined by histological methods (Hematoxylin-eosin staining and prolactin-immunostaining). Pituitary weight and prolactin concentration were measured. Extraced prolactin was analyzed by two-dimentional electrophoresis. Increase in prolactin positive cells was recognized in the pituitary glands of the group of 2 weeks by histological study. And adenoma-resembling findings were recognized in the pituitary gralds of the group of 6 weeks. Pituitary weight was markedly increased in the group of 8 weeks, and thereafter the pituitary weight was not increasing. Therefore, pituitary glands of 8 and 9 weeks were diagnosed as adenoma, and pituitary glands of the groups of 2, 4 and 6 weeks as hyperplasia by histological examination. Two-dimentional electrophoretical patterns fro the groups of 0-6 weeks were same. In the goups of 8 and 9 weeks, however, 3 spots neighboring the cathode in 7spots of molecular weight 24-25kD were disappeared. This disappearance of 3 spots was thought to be the change due to adenoma formation, and useful to distinguish between pituitary hyperplasia and adenoma.

[ISSN]0513-1731

[NCID]AN00243156