Lehy T, Accary J P, Dubrasquet M, Lewin M J
Gastroenterology. 1986 Mar;90(3):646-53. doi: 10.1016/0016-5085(86)91119-4.
The possible influence of growth hormone-releasing factor (GHRF) on epithelial cell proliferation in the digestive tract was investigated. Fasted young rats received five hourly subcutaneous injections of either GHRF or saline. They were killed 6, 12, or 18 h after the initial injection and 45 min after [3H]thymidine pulse labeling. At the time of death, blood was taken to determine circulating growth hormone and gastrin levels. After radioautography, DNA synthetic and mitotic activities were estimated in the fundic, antral, duodenal, jejunal, and colonic mucosae. Growth hormone-releasing factor significantly increased labeling indices 6, 12, and 18 h after the initial injection in fundic mucosa, and 6 and 18 h after injection in antral and duodenal mucosae. Furthermore, GHRF significantly increased mitotic indices at 12 h in fundic mucosa and at 12 and 18 h in jejunal mucosa. No effect was seen in the colon. At the three checkpoint times, circulating growth hormone showed no change, but plasma gastrin was increased in the rats treated with GHRF as compared with controls. However, whether the reported stimulatory effect of the GHRF on target cells is direct or indirect remains to be determined.
研究了生长激素释放因子（GHRF）对消化道上皮细胞增殖的可能影响。禁食的幼鼠每小时皮下注射一次GHRF或生理盐水，共注射五次。在初次注射后6、12或18小时以及[3H]胸腺嘧啶脉冲标记后45分钟将它们处死。处死时，采集血液以测定循环生长激素和胃泌素水平。放射自显影后，估计胃底、胃窦、十二指肠、空肠和结肠黏膜中的DNA合成和有丝分裂活性。生长激素释放因子在初次注射后6、12和18小时显著增加胃底黏膜的标记指数，在注射后6和18小时显著增加胃窦和十二指肠黏膜的标记指数。此外，GHRF在12小时显著增加胃底黏膜的有丝分裂指数，在12和18小时显著增加空肠黏膜的有丝分裂指数。在结肠中未观察到影响。在三个检查点时间，循环生长激素没有变化，但与对照组相比，接受GHRF治疗的大鼠血浆胃泌素增加。然而，GHRF对靶细胞的刺激作用是直接的还是间接的仍有待确定。
