新生大鼠胃肠道组织Ghrelin、PYY mRNA和蛋白及其下丘脑中受体mRNA的表达

目的 观察新生大鼠胃肠道组织Ghrelin、酪酪肽(PYY) mRNA和蛋白以及两者位于下丘脑的受体mRNA的表达变化,并探讨其与胃肠道成熟程度的关系.方法 选取0日龄和7日龄的新生大鼠各10只,分别采用Real-time PCR法和免疫组织化学法测定胃底组织Ghrelin mRNA和蛋白、结肠组织PYY mRNA和蛋白、下丘脑Ghrelin和PYY受体mRNA的表达.结果 0日龄大鼠胃底Ghrelin mRNA表达高于7日龄大鼠(P<0.05),结肠PYY mRNA表达则低于7日龄大鼠(P<0.01).0日龄大鼠胃肠道Ghrelin和PYY 蛋白表达均高于7日龄大鼠(P<0.05).0日龄与7日龄大鼠下丘脑Ghrelin和PYY受体mRNA的表达比较,差异均无统计学意义(P>0.05).结论 未成熟胃肠道组织Ghrelin和PYY蛋白合成分泌增加,起到促进胃肠道发育成熟的作用;而PYY mRNA与蛋白质表达的不平行状态提示该基因表达调控可能具有多样性.

Expression of Ghrelin and PYY mRNA and protein in gastrointestinal tract and their receptors mRNA in hypothalamus in neonatal rats

Objective To investigate the changes of expression of Ghrelin and peptide YY (PYY) mRNA and protein in gastrointestinal tract and their receptors mRNA in hypothalamus in neonatal rats, and explore their relationship with the maturity degree of gastrointestinal tract. Methods Ten neonatal rats of 0 day old (day 0 rats) and 10 neonatal rats of 7 days old (day 7 rats) were selected, and Real-time PCR and immunohistochemical staining were employed to detect the expression of Ghrelin mRNA and protein in gastric fundus tissues, PYY mRNA and protein in colon tissues and Ghrelin and PYY receptors mRNA in hypothalamus. Results The expression of Ghrelin mRNA in gastric fundus tissues of day 0 rats was significantly higher than that of day 7 rats (P<0.05), while the expression of PYY mRNA in colon tissues of day 0 rats was significantly lower than that of day 7 rats (P<0.01). The expression of Ghrelin and PYY protein in gastrointestinal tract tissues of day 0 rats was significantly higher than that of day 0 rats (P<0.05). There was no significant difference in the expression of Ghrelin and PYY receptors mRNA in hypothalamus between day 0 rats and day 7 rats (P>0.05). Conclusion The levels of Ghrelin and PYY synthesis and secretion may increase in immature gastrointestinal tract, which may promote the development and maturation of gastrointestinal tract. The unparalleled expression of PYY mRNA and protein indicates the diversity in the regulation of gene expression.