UP-REGULATION OF GH RECEPTOR AND GH BINDING-PROTEIN DURING PREGNANCY IN THE GH DEFICIENT RAT

Citation
Se. Gargosky et al., UP-REGULATION OF GH RECEPTOR AND GH BINDING-PROTEIN DURING PREGNANCY IN THE GH DEFICIENT RAT, Endocrine, 3(11), 1995, pp. 813-817
Citations number
39
Categorie Soggetti
Endocrynology & Metabolism
Journal title
ISSN journal
1355008X
Volume
3
Issue
11
Year of publication
1995
Pages
813 - 817
Database
ISI
SICI code
1355-008X(1995)3:11<813:UOGRAG>2.0.ZU;2-A
Abstract
During pregnancy there are dramatic changes in the endocrine and metab olic status of the mother: growth hormone (GH) is an important regulat or of growth and development. A proportion of CH is bound by specific GH binding proteins (GHBP) that closely resemble the GH receptor (GHR) . In the rodent both GHBP and the GHR are considered to be GH dependen t, and consequently during pregnancy the increase in serum GH is assoc iated with an increase in GHBP. To examine whether an increase in mate rnal GH is obligatory for elevation of maternal GHBP or GHR during pre gnancy, we used a unique GH-deficient (GHD) strain of rats, to avoid t he methodological complications of hypophysectomy and assessed serum G H, GHBP and hepatic GHR binding during the course of pregnancy. In GH normal rats, serum GH concentrations increased twofold and GHBP levels increased threefold; there was no change in hepatic GHR binding. In C HD rats, serum GH concentrations were low and did not increase during pregnancy. Nonetheless, levels of both serum GHBP and hepatic GHR bind ing increased to that measured in normal rats. Thus, an increase in ma ternal GH concentration is not required for the gestational upregulati on of maternal GHBP or hepatic GHR binding, suggesting that other horm ones may be essential in modulating the GH axis during pregnancy.