Age-related changes in ghrelin function, ghrelin concentration and ghrelin related molecules expression in the growing chickens.

Ghrelin收缩鸡的胃肠道。生长激素释放肽诱导的收缩和生长激素促分泌素受体（GHS-R1 a）mRNA的表达在前胃下降，这取决于年龄。腺胃和血浆中Ghrelin的浓度在孵化后增加，并在30天达到平台期。生长激素释放肽和生长激素释放肽-O-乙酰转移酶（GOAT）mRNA的表达也倾向于根据年龄而减少。ghrelin mRNA的表达与血浆ghrelin水平无相关性。生长激素释放肽浓度与GHS-R1 a和GOAT mRNA表达之间的反比关系表明生长激素释放肽诱导的生长激素释放肽受体和合成酶的下调。生长发育期脑内ghrelin、GOAT和GHS-R1 a mRNA的表达具有明显的区域依赖性。以上结果表明生长期鸡脑和胃肠道ghrelin系统的生理功能发生了变化。

Ghrelin contracted a chicken gastrointestinal tract. The ghrelin-induced contraction and expression of growth hormone secretagogue receptor (GHS-R1a) mRNA in the proventriculus decreased depending on age. Ghrelin concentrations in the proventriculus and plasma increased after hatching and reached plateau at 30 days. Expression of ghrelin and ghrelin-O-acetyltransferase (GOAT) mRNAs also tended to decrease depending on age. Expression of ghrelin mRNA did not show any correlation with plasma ghrelin. Inverse relationships between ghrelin concentration and GHS-R1a and GOAT mRNAs expression are indicative for a ghrelin-induced downregulation of the ghrelin receptor and synthetic enzyme. The expression pattern of ghrelin, GOAT and GHS-R1a mRNAs in the brain distinctly change in region-dependent manner on growing stage. The present results indicated that physiological role of ghrelin system changes in the brain and gastrointestinal tract of growing chickens.