The Analysis of Physiological Roles of circulating ghrelin

点击翻译按钮获取中文摘要

In this study, we generated a transgenic mouse that expresses human diphtheria toxin (DT) receptor cDNA in ghrelin-secretion cells (GPDTR-Tg mice). Administration of DT to this mouse ablates ghrelin-secretion cells in a controlled manner. Four days after injection of DT into GPDTR-Tg mice, ghrelin-secreting cells were ablated, and plasma levels of ghrelin were markedly decreased. Daily food intake of these animals, however, was not affected. Three-week-old GPDTR-Tg mice were then treated with DT twice a week for five weeks. Although plasma ghrelin levels were reduced, GPDTR-Tg mice did not display any decreases in serum GH or IGF-1 levels or any growth retardation. Our results strongly suggest that circulating ghrelin does not play a crucial role in either feeding behavior or somatic growth.