Carnevali O, Sabbieti M G, Mosconi G, Polzonetti-Magni A M
Department of Biology (MCA), University of Camerino, Italy.
Mol Cell Endocrinol. 1995 Oct 30;114(1-2):19-25. doi: 10.1016/0303-7207(95)03637-m.
In Rana esculenta in an in vitro system, hepatic vitellogenin synthesis can be induced by growth hormone in both sexes. In this study: (1) the ability of this hormone to induce transcription of the VTG gene was determined, and (2) this ability was compared with that of estradiol-17 beta. The results indicate that growth hormone stimulates VTG mRNA transcription both in vivo and in vitro, in both sexes. The levels of mRNA are related to protein levels in the medium. In addition, seasonal variation occurs in the VTG gene transcription under growth hormone and estradiol-17 beta; indeed the more active inducer was growth hormone during the reproductive period and estradiol-17 beta during the preproductive phase.
在体外系统中，对于食用蛙而言，生长激素可诱导两性肝脏中卵黄蛋白原的合成。在本研究中：（1）测定了该激素诱导VTG基因转录的能力，（2）并将此能力与17β-雌二醇的能力进行了比较。结果表明，生长激素在体内和体外均可刺激两性的VTG mRNA转录。mRNA水平与培养基中的蛋白质水平相关。此外，在生长激素和17β-雌二醇作用下，VTG基因转录存在季节性变化；实际上，在繁殖期，活性更强的诱导剂是生长激素，而在繁殖前期是17β-雌二醇。
