Dopamine Responsiveness of Human Prolactinoma Cells as Determined by the Reverse Hemolytic Plaque Assay

Endocrine Journal

NOBUMASA KUWANA²  YASUHIRO KOJIMA²  FUKUKO KIMURA¹  JUN ARITA¹ 

[1] Department of Physiology, Yokohama City University School of Medicine;Department of Neurosurgery, Yokohama Minami Kyosai Hospital

关键词: Reverse hemolytic plaque assay;    Prolactinoma;    Dopamine;    Bromocriptine;   

DOI  :  10.1507/endocrj.42.355

学科分类：内分泌与代谢学

来源: Japan Endocrine Society

【 摘 要 】

References(26)Cited-By(3)The responsiveness in vivo to dopamine of prolactin (PRL) secretion in patients with prolactinoma was compared with that in vitro of single cells obtained from the same prolactinomas by surgical operations. Six patients with prolactinoma showing various degrees of hyperprolactinemia were challenged by bromocriptine suppression test (2.5mg, peroral) before operation. Bromocriptine administration caused a decrease in the serum PRL concentration ranging 24-95% and there was no correlation between the basal PRL level and bromocriptine-induced inhibition. Monodispersed pituitary cells obtained from the prolactinomas by operation were subjected to a reverse hemolytic plaque assay for PRL to determine PRL secretion at the single cell level under basal conditions as well as in response to dopamine. The percentage of plaque-forming cells under basal conditions ranged 15-55% among the prolactinomas. The percentage of plaque-forming cells and plaque area were decreased in a dose-dependent manner by 10-7-10-5M dopamine for the pituitary cells obtained from some adenomas but not for those from other adenomas. When the inhibition rates in vitro due to 10-5M dopamine in these two parameters were compared with the inhibition rate in vivo in the serum PRL concentration due to bromocriptine, it was found that there was a significant correlation between them. These results show that the reverse hemolytic plaque assay can be used to determine in vitro responsiveness to dopamine of PRL secretion from single prolactinoma cells. We conclude that 1) the relative abundance of PRL-secreting cells varies among prolactinomas; and 2) there is a correlation between in vivo and in vitro responsiveness of prolactinoma cells to dopaminergic inhibition.

【 授权许可】

Unknown