赤霉素对雌性大鼠早期生长发育及胰岛素样生长因子表达水平的影响

Effects of gibberellins on early development and IGF-1 expression in female rats

目的探讨植物生长调节剂赤霉素对雌性SD大鼠生长发育及胰岛素样生长因子(IGF-1)表达水平的影响。方法选择刚断乳雌性SD大鼠40只,随机分为4组,即对照组,低、中、高赤霉素剂量组,分别按照0、2、100和200mg/kg赤霉素剂量经口灌胃,连续15天,每天记录身长、体重、阴道开口情况。染毒结束,剖杀受试动物,获得肝脏、卵巢、子宫,计算脏器系数。提取肝组织RNA进行RT-PCR,检测肝内IGF-1、胰岛素样生长因子捆绑蛋白(IGFBP-1)基因的表达水平。结果各组间大鼠的身长、体重,阴道开口时间,子宫、卵巢的脏器系数差异无显著性(P>0.05),肝组织内IGF-1、IGFBP-1平均表达水平差异亦无显著性(P>0.05),但高剂量组部分样本出现IGF-1、IGFBP-1表达强度倒置的现象。高剂量组动物的肝脏系数小于对照组(P<0.05)。结论在0～200mg/kg剂量范围赤霉素接触对雌性SD大鼠生长发育、肝脏内IGF-1及其捆绑蛋白的表达影响不明显,但200mg/kg剂量的赤霉素摄入可能对其肝脏产生损伤。

Objective To explore the effects of plant growth regulator gibberellin on early development and IGF-1 expression in female rats. Methods Forty weaned female SD rats were randomly divided into four groups and fed with basic diet. Gibberellin was administered intragastrically at the levels of 0,2.0,100. 0 and 200.0 mg/kg respectively for 15 days. Body weight and body length were measured weekly and the time of vaginal opening was observed every day. Liver, uterus and ovary were dissected after exposure for 15 days. Total RNA of liver was extracted and the expression of IGF-1 and IGFBP-1 mRNA was detected by RT-PCR. Results Compared with the control group,no significant differences of body weight, body length, vaginal opening time, as well as the organ coefficients of liver, uterus and ovary were observed in gibberellin-treated groups. There was no significant change on the expressions of IGF-1 and IGFBP-I in the liver ofgibberellin-treated groups,although the expression of IGFBP-1 was more than IGF-1 in a few samples. Organ coefficient of liver in high dose group was significantly lower than that in the control group（P 〈 0. 05）. Conclusion Gibberellin does not cause abnormal change on growth and development as well as the expression of IGF-I and IGFBP-1 in liver of female SD rats,but at the level of 200. Omg/kg gibberellin may induce damages in liver.