碘缺乏和甲状腺功能减退对大鼠仔鼠海马钙调磷酸酶表达的影响

Effect of Iodine Deficiency and Hypothyroidism on the Protein Expressions of Calcineurin in the Hippocampus of Pups

目的观察碘缺乏和甲状腺功能减退对大鼠仔鼠海马钙调磷酸酶蛋白表达的影响。方法健康2月龄雌性Wistar大鼠,交配妊娠后,取孕鼠28只,按体质量随机分成对照组、甲状腺功能减退组和碘缺乏组,甲状腺功能减退组根据饮水中含丙基硫尿嘧啶剂量分为5ppm组和15ppm组,每组7只孕鼠。分别于出生后7d(PN7)、14d(PN14)和31d(PN21)时,每组随机取5只仔鼠,灌流固定大脑,进行组织病理切片和免疫组化染色,观察分析海马钙调磷酸酶的表达。结果PN14和PN21时,在海马CA1和CA3区15ppm组和碘缺乏组仔鼠海马钙调磷酸酶表达显著高于对照组(P<0.05),而海马DG区则相反。PN7时,各区均几乎观察不到阳性反应产物,各组间蛋白表达无显著差异。结论碘缺乏和甲状腺功能减退可增加海马CA1和CA3区钙调磷酸酶的蛋白表达。

Objective To observe the effect of iodine deficiency and hypothyroidism on the protein expressions of calcineurin in the hippocampus of pups. Methods Female Wistar rats （ n=28 ） after pregenaney were randomly divided into control group, hypothyroid group and iodine deficient group. According to the dose of propylthiouracil （PTU） in the fed water, hypothyroid group was divided into 5 ppm group and 15 ppm group （7 rats in each group）. Totally 5 pups from each group were sacrificed and perfused intmcardially in postnatal day （PN） 7,PNI4 and PN21. Brains were removed,fixed and sectioned coronally. All sections were observed and analysed for the protein exression of calcineurin by immunohistocheroistry in the hippecampus CA1 ,CA3 and DG regions. Results In PN14 and PN21 ,protein levels of calcineurin in CA1 and CA3 regions of the hippocampus in iodine-deficient and 15 ppm treatment groups were significantly higher than those of the controls （P 〈 0.05 ） and in DG region, the contrary was true. In PN7, the positive products were scarely observated in each region and the protein expression was no significantly different in all four groups. Conclusion Iodine deficiency and hypothyroidism may increase the protein expression of calcineurin.