Ghrelin及受体GHSR表达变化与宫内发育受限仔鼠追赶生长的关系

Relationship between Ghrelin and growth hormone secretagogue receptor expression and catch-up growth in rats with intrauterine growth restriction

摘要:

目的：了解Ghrelin及生长激素释放促分泌素受体（GHSR）表达变化与宫内发育受限（IUGR）仔鼠追赶生长的关系。方法：采用妊娠期食物限制法建立IUGR大鼠模型，孕鼠分娩后，获得限食小于胎龄（SGA）仔鼠和限食适于胎龄（AGA）仔鼠为实验组，不限食适于胎龄（AGA）仔鼠为对照组。于0、20、40日龄取胃底和下丘脑组织，实时荧光定量PCR法（real-time FQ-PCR）分别测定Ghrelin mRNA和GHSR mRNA；免疫组织化学法测定Ghrelin蛋白和GHSR蛋白。结果：0日龄限食SGA组仔鼠胃底组织中Gherlin mRNA和蛋白表达均高于限食AGA组和对照组，下丘脑GHSR mRNA的表达低于限食AGA组和对照组；20日龄SGA组追赶生长仔鼠胃底Ghrelin蛋白、下丘脑GHSR mRNA和蛋白的表达高于SGA未追赶生长和对照组仔鼠；40日龄时3组间则差异无统计学意义（P>0.05）。结论：Ghrelin-GHSR可能参与了宫内IUGR胎鼠的生理调节或病理过程，且可能在出生后参与了SGA个体早期追赶生长的调控。

Abstract:

OBJECTIVE: To study the relationship between Ghrelin and growth hormone secretagogue receptor (GHSR) expression and the catch-up growth in rats with intrauterine growth restriction (IUGR). METHODS: The rat model of IUGR was established by food restriction during pregnancy. The small for gestational age (SGA) and appropriate for gestational age (AGA) rat pups from the pregnant rats were used as the experimental group. The AGA rat pups from the pregnant rats without food restriction served as the control group. The samples from the stomach fundus and hypothalamus were taken postnatal days 0, 20 and 40. Ghrelin mRNA and GHSR mRNA expression were determined by real-time fluorescence quantitive PCR (real-time FQ-PCR). Ghrelin protein and GHSR protein expression were examined by immunohistochemistry (IHC). RESULTS: At postnatal day 0, both Gherlin mRNA and protein levels in the stomach fundus were significantly higher, while GHSR mRNA expression in the hypothalamus were significantly lower in SGA rats from food restriction group than those in AGA rats from restriction and control groups. At postnatal day 20, the ghrelin protein expression in the stomach of fundus, and GHSR mRNA and protein expression in the hypothalamus in SGA catch-up rats were significantly higher than those in SGA non-catch-up growth rats and AGA rats from the control group. At postnatal day 40, there were no significant differences among SGA catch-up growth rats, SGA non-catch-up growth rats and normal AGA rats. CONCLUSIONS: Ghrelin-GHSR might be involved in the physiological regulation and pathological process in IUGR rats. It is also possibly involved in the regulation of catch-up growth in the early life of SGA rats.［Chin J Contemp Pediatr, 2010, 12 (7):563-568］