Effect of hormones on expression of prolactin receptor messenger ribonucleic acids in pancreatic islets of adult female mice in vitro.
We studied the effects of hormones on expression of prolactin receptor (PRL-R) mRNA in pancreatic islets of adult female mice in vitro. We quantified mRNA expression in small amounts of the islet tissue by competitive PCR and one-sided competitive PCR. Fifty pancreatic islets from adult female mice were cultured in a wall for 4 days with or without ovine prolactin (PRL), bovine growth hormone or estradiol-17 beta. PRL (1 microgram/ml) significantly increased the insulin secretion and the amount of PRL-R mRNA relative to that of beta-actin mRNA. Growth hormone (1 microgram/ml) also increased the relative amount of PRL-R mRNA, although it did not significantly increase the insulin secretion. Neither insulin secretion nor the relative amount of PRL-R mRNA was affected by estradiol (100 ng/ml). The ratio of the short form to the long form of PRL-R mRNA was not altered by these hormones. The present observation that PRL increased PRL-R mRNA expression in pancreatic islets thus suggests the possibility that PRL up-regulates the tissue sensitivity to PRL itself during lactation.
Matsuda
M
M
Department of Biological Sciences, Graduate School of Science, University of Tokyo, Japan.
Mori
T
T
D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D013006:Growth Hormone / Q000494:pharmacology*; D007515:Islets of Langerhans / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D011388:Prolactin / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis*; D011981:Receptors, Prolactin / Q000096:biosynthesis*
D004967:Estrogens; D012333:RNA, Messenger; D011981:Receptors, Prolactin; D011388:Prolactin; D013006:Growth Hormone