摘要目的 研究母乳对断乳期和童年期SD大鼠胃肠道Ghrelin及酪酪肽(PYY)分泌的影响.方法 将40只新生SD大鼠随机分为母乳组和配方奶组,母乳组予正常母乳喂养；配方奶组予人工管饲配方奶喂养,仔鼠从第7天开始喂养直至满3周为止,断乳期后2组大鼠采取同种饲料定时喂养.分别于日龄21 d、50 d时采用实时荧光定量PCR法检测胃底组织和结肠组织中Ghrelin mRNA和PYYmRNA表达；同时采用免疫组织化学法检测Ghrelin及PYY蛋白表达.结果 2组大鼠不同时期体质量及胃肠道黏膜发育水平比较差异无统计学意义(P＞0.05)；母乳组21 d及50 d胃肠道Ghrelin、PYY mRNA表达和蛋白表达均高于配方奶组(P均＜0.05).结论 母乳喂养大鼠断乳期胃肠道Ghrelin、PYY分泌高于配方奶喂养大鼠,并且可持续至童年期.母乳可能通过影响子代胃肠道激素分泌途径参与其摄食调节与能量平衡.

abstractsObjective To study the effect of breast milk on secretion of Ghrelin and Peptide YY (PYY)during different periods in SD rats.Methods Sprague-Dawley (SD) rats were randomly divided into breast milk-fed group(BG) and formula-artificial fed group(FG) with 20 in each group.After 21 days both of the 2 groups were fed by same forage.Ten of each group were experimentized in day 21 equivalently weaning period,and rest rats were experimentized at the 50th day equivalently childhood.Real-time PCR was used to determine the mRNA of PYY,Ghrelin from gastric,colon.Immunohistochemistry was used to determine Ghrelin,PYY protein expression in the gastrointestinal tract tissues.Results There were no difference between body weight and gastrointestinal mucosal development of 2 rat groups in day 21 and day 50(P ＞0.05),mRNA and protein expression of Ghrelin and PYY in breast milk-fed group were higher than formula-artificial fed group in both day 21 and day 50 (all P ＜ 0.05).Conclusions The Ghrelin and PYY levels of breast milk-fed rats is higher than formula-artificial fed ones,and this phenomenon continues to their childhood.Breast milk protects offspring from obesity by influencing the secretion of brain-gut peptide and has long-term consequences on the regulation of food intake and energy balance from neonatal period to their later life.