Ghrelin mRNA和蛋白在小于胎龄仔鼠胃底组织中表达的变化

Changes of Ghrelin mRNA and Protein Expression in Fundus of Stomach in Small for Gestational Age Rats

目的了解胃底组织Ghrelin mRNA和蛋白表达与小于胎龄(SGA)仔鼠追赶生长的关系。方法采用妊娠中后期食物摄入限制法获得SGA和适于胎龄(AGA)仔鼠,并设对照组。孕鼠分娩后收获仔鼠,分别于0、20、40日龄3个时间点每组随机抽取仔鼠10只,取其胃底组织。采用实时荧光定量PCR法测定其Ghrelin mRNA,免疫组织化学法测定Ghrelin蛋白在各组仔鼠胃底组织中的表达。结果0日龄限食组SGA仔鼠胃底组织Gherlin mRNA表达高于限食组AGA仔鼠和对照组AGA仔鼠(Pa<0.05);20日龄和40日龄的SGA未追赶生长仔鼠、SGA追赶生长仔鼠和对照组AGA仔鼠胃底组织Gherlin mRNA表达均无统计学差异(Pa>0.05)。0日龄限食组SGA仔鼠胃底组织Ghrelin免疫阳性细胞的积分光密度(A)值高于限食组AGA和对照组AGA仔鼠(Pa<0.05);20日龄SGA追赶生长仔鼠胃底组织中Ghrelin免疫阳性细胞的A值高于SGA未追赶生长仔鼠和对照组AGA仔鼠(Pa<0.05);40日龄时3者间无统计学差异(P>0.05)。结论0日龄SGA仔鼠Ghrelin mRNA在胃底组织中表达增加,提示Ghrelin可能在宫内就开始参与宫内发育迟缓胎鼠的生理调节或病理过程,或是宫内的营养状况和环境变化对胎鼠胃底细胞的生理功能产生了影响,使Ghrelin mRNA表达上调;20日龄追赶生长SGA仔鼠胃底Ghrelin表达的变化进一步提示,Ghrelin可能参与了SGA早期的追赶生长调控。

Objective To explore the changes of Ghrelin mRNA and protein expression in fundus of stomach in small for gestational age （SGA） rats and analyze the relationship with the catch - np growth of SGA rats. Methods The SGA and appropriate for gestational age （AGA） rat models were established by food restriction during the second and the third trimester of pregnancy. The newborn rats were acquired alter delivery,among which 10 rats were selected randomized from SGA group and control group at postnatal day 0,day 20 and day 40. The fundus of stomach were taken to determine Ghrelin mRNA and protein expression, in which real -time fluorescent quantitive PCR （real -time FQ - PCR） and immunohistochemistry （IHC） were used, respectively. Results At postnatal day 0, fundus of stomach Gherlin mRNA expression was higher in SGA rats from food restriction groups than those in AGA rats from tood restriction and control groups（ Pa 〈0.05 ）. At postnatal day 20 amt day 40, there was no significant difference in filndus of stomach Gherlin mRNA expression among SGA non - catch - up rats, SGA catch - up rats and control AGA rats（ P 〉 0.05 ）. At postnatal day 0,tundus of stomach Gherlin A score in SGA rats from food restriction groups was higher than AGA rats from food restriction and eontr.l groups（ P 〈0.05 ）. Ghrelin A score in SGA catch - up rats was higher than SGA non - catch - up rats and contrail AGA rats（ P 〈 0.05 ） at postnatal day 20, and there was no significant difference among them at postnatal ,lay 40（ P 〉 0.05 ）. Conclusions The increase of Ghrelin mRNA expression in fundus of stomach of SGA rats of postnatal day 0 suggest that Ghrelin might be involved in the physiological regnlation or pathological process of intrauterine grouth retardation,and intrauterine nutritional status or endoerine circumstances may have effects on the cells of gastric fundus of the fetuses, which results in the up - regulation of Ghrelin expression. The ehanges of endogastric Ghrelin expression in postnatal day 20 catch - up SGA rats suggests that Ghrelin might be involved in the regulation of catch -up growth in their early life,which still need to be deternfined.