Studies on Phenotype of Reproduction and Production of Human Growth Hormone(hGH) with Transgenic Rats I. Changes in Endogenous Grwoth Hormone Secretion and Onset of Puberty in hGH Transgenic Rats

Human 성장호르몬을 도입한 Transgenic Rats의 작출과 번식표현형에 관한 연구 I. mWAP/hGH을 도입한 Rat의 Endogenous GH분비 변화와 성성숙에 미치는 영향

A chimeric gene comprising murine whey acidic protein(mWAP) and human growth hormone(hGH) was used to produce transgenic rats express hGH and secrete it into the blood. Two lines of transgenic rats carrying the mWAP/hGH construct were established; High line was characterized by relatively high levels of serum hGH, and low line had relatively low levels. The secretory profiles of rat GH(rGH) as well as hGH, the transgene product, were obtained in transgenic males and females of low line; both hGH and rGH serum levels were flattened with no episodic fluctuations, and the overall mean concentration of rGH was significantly lower than in normal littermates. Although the animals of High line showed an acceles, as assessed by vaginal opening and occurrence of first ovulation, advanced by 7∼8 days in both lines of animals. Accordingly, the body weight at puberty of low line transgenic females was much lower than that of normal littermates, indicating that continuous hGH expression could induce precocious puberty without enhancing the growth rate.