Warzecha Zygmunt, Dembiński Artur, Ceranowicz Piotr, Dembiński Marcin, Cieszkowski Jakub, Bielański Władysław, Pawlik Wiesław W, Kuwahara Atsukazu, Kato Ikuo
Department of Physiology, Jagiellonian University Medical College, 16 Grzegórzecka Street, 31-531 Kraków, Poland.
Eur J Pharmacol. 2006 Jan 4;529(1-3):145-50. doi: 10.1016/j.ejphar.2005.10.065. Epub 2005 Dec 9.
Ghrelin is a circulating growth hormone-releasing peptide primarily isolated from human and rat stomach. The aim of present study was to investigate the effect of ghrelin administration on gastric growth in suckling, and young peripubertal 7-week-old rats. Rats were treated for 7 days with saline or ghrelin (4, 8 or 16 nmol/kg/dose) intraperitoneally twice a day. Suckling rats were treated from the fist postnatal day.
Treatment with ghrelin did not affect animal weight in suckling rats; whereas in 7-week-old animals, administration of ghrelin caused a significant increase in body weight. In suckling rats, ghrelin decreased the gastric weight, DNA synthesis and DNA content. In young 7-week-old peripubertal rats, treatment with ghrelin increased food intake and animal body weight. This effect was accompanied with a significant increase in gastric mucosa weight, DNA synthesis and DNA content. Treatment with ghrelin increased serum level of growth hormone in all rats tested, but this result was much higher in 7-week-old peripubertal rats than in suckling rats. Serum level of insulin-like growth factor-1 was not affected by ghrelin administration in suckling rats. In contrast, ghrelin caused a significant increase in serum level of insulin-like growth factor-1 in 7-week-old peripubertal rats. We conclude that administration of ghrelin exhibits biphasic effect on gastric growth in young rats: in suckling rats, ghrelin reduces gastric growth, whereas in young 7-week-old animals, treatment with ghrelin stimulates gastric growth. The growth-promoting effect of ghrelin in the stomach seems to depend on the stimulation of food intake and the release of insulin-like growth factor-1.
胃饥饿素是一种主要从人和大鼠胃中分离出的循环生长激素释放肽。本研究的目的是探讨给予胃饥饿素对乳鼠以及7周龄青春期前幼鼠胃生长的影响。大鼠每天腹腔注射生理盐水或胃饥饿素（4、8或16 nmol/kg/剂量），共治疗7天，每天2次。乳鼠从出生后第一天开始治疗。
给予胃饥饿素对乳鼠体重没有影响；而在7周龄的动物中，给予胃饥饿素导致体重显著增加。在乳鼠中，胃饥饿素降低了胃重量、DNA合成和DNA含量。在7周龄青春期前幼鼠中，给予胃饥饿素治疗增加了食物摄入量和动物体重。这种作用伴随着胃黏膜重量、DNA合成和DNA含量的显著增加。给予胃饥饿素使所有受试大鼠的生长激素血清水平升高，但这一结果在7周龄青春期前幼鼠中比在乳鼠中高得多。胃饥饿素给药对乳鼠的胰岛素样生长因子-1血清水平没有影响。相比之下，胃饥饿素使7周龄青春期前幼鼠的胰岛素样生长因子-1血清水平显著升高。我们得出结论，给予胃饥饿素对幼鼠胃生长具有双相作用：在乳鼠中，胃饥饿素减少胃生长，而在7周龄幼鼠中，给予胃饥饿素刺激胃生长。胃饥饿素在胃中的促生长作用似乎取决于对食物摄入的刺激和胰岛素样生长因子-1的释放。
