哺乳期过度喂养对断乳后大鼠胃组织脑肠肽生长激素释放肽及血清瘦素水平的影响

目的 观察哺乳期过度喂养大鼠断乳后胃组织脑肠肽生长激素释放肽(Ghrelin)表达和循环中瘦素(Leptin)水平的变化,探讨早期过度喂养导致成年期代谢综合征的病理生理机制.方法 应用SD大鼠模型,雄仔出生后分为正常喂养组(NF组,每窝10只)和哺乳期过度喂养组(OF组,每窝3只).出生3周断乳,均给予正常饮食.ELISA法及放射免疫分析法分别测定其血清Leptin、Ghrelin及胰岛素水平,实时定量PCR及免疫组织化学测定其胃组织Ghrehn mRNA和蛋白表达水平.结果 OF组大鼠从出生第2周起体质量持续显著高于NF组(P＜0.05),并在16周时出现糖耐量受损,胰岛素水平显著增加(P＜0.05).NF组和OF组血清Leptin水平自青春期迅速增加,第4周起,OF组epti水平显著高于NF组(F＝7.94,P＜0.05),血清Ghrelin在各时间点上均无组间差异(Pa＞0.05).NF组和OF组胃组织Ghrelin mRNA的表达均随年龄逐渐增加,在8周时达高峰(P＜0.05),但2组间在各个时间点上差异均无统计学意义(Pa＞0.05).免疫组织化学显示Ghrelin阳性细胞面积的变化趋势同mRNA表达基本一致.结论 大鼠哺乳期过度喂养可导致其成年期肥胖和胰岛素抵抗.哺乳期过度喂养对大鼠胃组织Ghrelin表达和分泌无明显影响,但血清kptin水平持续升高,长期食欲调控的抵抗和代谢失衡可能参与成年期肥胖和代谢紊乱的发生.

Effect of Over-Feeding during Lactation Period on Expressions of Ghrelin in Gastric Tissue and Leptin inSerum in Adult Rats

Objective To observe the effects of over-feeding during lactation period on the ghrelin expression and leptin levels in gastric tissue and serum,and explore the pathophysiology of metabolic syndrome induced by over-feeding. Methods Male Sprague-Dawley rats pup litters were adjusted to litter sizes of 10 rats(normal feeding group,NF group) or 3 rats(over-feeding group,OF group) in postnatal day 3,and then standard chow was given after weaning(postnatal day 21).Serum hormones insulin was assayed by specific r...