First Author | González L | Year | 2001 |
Journal | Growth Horm IGF Res | Volume | 11 |
Issue | 1 | Pages | 34-40 |
PubMed ID | 11437472 | Mgi Jnum | J:127758 |
Mgi Id | MGI:3764781 | Doi | 10.1054/ghir.2000.0187 |
Citation | Gonzalez L, et al. (2001) Growth hormone (GH) and estradiol regulation of membrane-associated GH binding protein and GH receptors in GH releasing hormone transgenic mice. Growth Horm IGF Res 11(1):34-40 |
abstractText | Growth hormone (GH) releasing hormone (GHRH) transgenic mice were used to examine the influence of GH on GH receptor (GHR) and membrane-associated GH binding protein (MA-GHBP) levels by means of specific radioimmunoassays and Western blot analysis, since MA-GHBP was described as the major constituent of somatogenic binding to liver membranes in mice. In transgenic animals, a 10-fold increment over normal values was found for hepatic somatogenic binding that could be accounted for by a 3--4-fold increase in GHR and a 9-fold augmentation of MA-GHBP levels. The apparent molecular weight of MA-GHBP was smaller than that of serum GHBP, a difference that was partially abolished by endoglycosidase F digestion. In vivo treatment of female mice with 17 beta-estradiol led to an unexpected down-regulation of MA-GHBP and GHR by 60--75% only in transgenic animals. MA-GHBP and GHR levels are strongly up-regulated by GH, although MA-GHBP up-regulation is much more important than that of GHR. |