Influence of the expression of the human growth hormone releasing factor gene on hormone levels in a transgenic rabbit
Koval', T.I.; Khamidov, D.K.; Andreeva, L.E.; Gazarian, K.G.
Problemy Endokrinologii 37(6): 51-54
1991
ISSN/ISBN: 0375-9660 PMID: 1788215 Document Number: 370437
A transgene rabbit with the human growth hormone releasing factor gene was produced by a method of microinjections into fertilized oocytes; a mouse metallothionein I gene was used as a promoter. Gene expression was accompanied by a phenotypical effect, expressed in increasing the rates of development. The maximum difference among the transformant, transplants and control was revealed on the 30-45th day of postnatal development. Analysis of the hormonal status of the transgene animal has shown change in the levels of the majority of hormones: a 6-10-fold increase in insulin; a 2-3-fold increase in the level of triiodothyronine, thyroxin; a reduced somatostatin concentration, a two-fold decrease in the level of progesterone, and a four-fold decrease in the level of testosterone. Activation of the promoter zone with Zn++ salts for 5 weeks resulted in a further increase in the transformant body mass by 10%. However blood hormone levels in the transgene rabbit returned to normal. Proceeding from the above it can be assumed that exogenous gene expression probably increased somatotropin secretion which determined dysfunction of most of the endocrine glands; the effect of somatotropin was probably insulin-mediated.