孕期尼古丁暴露子代大鼠饲喂高脂饮食对下丘脑-垂体-肾上腺轴敏感性的影响及发生机制

发布时间：2018-03-13 12:00

本文选题：尼古丁　切入点：海马　出处：《中国药理学与毒理学杂志》2017年01期 　论文类型：期刊论文

【摘要】：目的观察孕期尼古丁暴露(PNE)所致子代大鼠高脂饮食下下丘脑-垂体-肾上腺(HPA)轴应激高敏感性改变,并探讨其发生机制。方法受孕Wistar大鼠从孕9~20 d sc给予尼古丁2 mg·kg-1。自然出生仔鼠断奶后给予高脂饮食喂养至20周(PW20),其中一半仔鼠从PW17至PW20给予3周不可预计性慢性刺激(UCS)。HE染色观察组织形态学改变,放免试剂盒和ELISA分别检测大鼠血清促肾上腺皮质激素(ACTH)及皮质酮(CORT)水平,PCR检测ACTH释放激素(CRH)、精氨酸加压素(AVP)、囊泡谷氨酸转运蛋白2(VGlu T2)、谷氨酸脱羧酶65(GAD65)、盐皮质激素受体(MR)、糖皮质激素受体(GR)和谷氨酸脱羧酶67(GAD67)等相关基因的m RNA表达。结果正常对照组雌、雄仔大鼠经UCS刺激后,血清ACTH和CORT分别升高了1.96倍(P0.01),1.63倍(P0.01)和3.24倍(P0.01),3.54倍(P0.01),PNE组雌、雄仔大鼠经UCS刺激后,血清ACTH和CORT分别升高了3.96倍(P0.01),3.04倍(P0.01)和5.98倍(P0.01),5.22倍(P0.01)。与UCS处理的正常对照组仔大鼠相比,UCS处理的PNE组雌、雄仔大鼠下丘脑AVP m RNA表达分别升高了2.04倍(P0.01)和1.13倍(P0.05),雌性下丘脑CRH m RNA表达和VGlu T2/GAD65 m RNA比值分别升高了2.49倍(P0.01)和1.14倍(P0.01)。全部PNE组雌、雄仔大鼠海马各区均出现不同程度的病理损伤,表现为神经元数量减少、排列稀疏和细胞间隙增大。与无UCS处理的正常对照组相比,无UCS处理的PNE雌、雄仔大鼠海马MR/GR m RNA比值分别降低了88.0%和86.0%(P0.01),GAD67 m RNA表达分别升高了1.38倍和1.97倍(P0.05);与UCS处理的正常对照组相比,UCS处理的PNE组雌性仔大鼠海马GAD67 m RNA表达升高了2.17倍(P0.05)。结论 PNE可致高脂饮食成年子代大鼠HPA轴应激高敏感性发生,其机制可能与海马MR/GR比值失衡、GAD67表达上调,进而介导下丘脑局部潜在兴奋性增加有关。
[Abstract]:Objective to observe the changes of hypersensitivity of hypothalamus-pituitary-adrenal (HPA) axis stress induced by nicotine exposure in pregnant rats under high-fat diet. Methods pregnant Wistar rats were given nicotine 2 mg 路kg-1.After weaning, they were fed with high-fat diet for 20 weeks, and half of them were given unpredictable chronic 3 weeks from PW17 to PW20. The histopathological changes were observed by stimulating UCSN. He staining. Radioimmunoassay kit and ELISA were used to detect the serum levels of ACTH and Cort, respectively. ACTH releasing hormone (ACTH), arginine vasopressin (AVP), vesicular glutamate transporter 2 (VGlu T2N), glutamate decarboxylase 65 (GAD65) and salt corticosteroid were detected by PCR. The expression of m RNA in the related genes, such as receptor MRN, glucocorticoid receptor GRG and glutamate decarboxylase 67GAD67. After stimulated by UCS, the serum ACTH and CORT of male rats were increased by 1.96 times (P 0.01), 1.63 times (P 0.01) and 3.24 times (P 0.01) and 3.54 times (P 0.01) respectively. The male rats were stimulated by UCS. Serum ACTH and CORT were increased by 3.96 times (P 0.01) and 5.98 times (P 0.01) and 5.22 times (P 0.01) respectively. Compared with the control group treated with UCS, the female of PNE group treated with UCS was higher than that of control group. The expression of AVP m RNA in hypothalamus of male rats was increased by 2.04 times (P 0.01) and 1.13 times (P 0.05), and the expression of CRH m RNA and VGlu T 2 / GAD 65 m RNA in female hypothalamus were increased by 2.49 times (P 0.01) and 1.14 times (P 0.01) respectively. Pathological damage was observed in the hippocampal regions of male rats. The number of neurons was decreased, the arrangement of neurons was sparse and the intercellular space was enlarged. Compared with the normal control group without UCS treatment, the female with PNE without UCS treatment was not treated with PNE. The ratio of MR/GR m RNA in hippocampus of male rats decreased by 88.0% and 86.0, respectively, and the expression of GAD67m RNA increased by 1.38 times and 1.97 times, respectively, and the expression of GAD67 m RNA increased by 2.17 times compared with the normal control group treated with UCS. Conclusion PNE can induce high sensitivity of HPA axis stress in adult offspring of high fat diet. The mechanism may be related to the up-regulation of GAD67 expression in hippocampus due to the imbalance of MR/GR ratio, which may mediate the increase of local potential excitability in hypothalamus.
【作者单位】：武汉大学基础医学院药理学系;发育源性疾病湖北省重点实验室;
【基金】：国家自然科学基金(81220108026) 国家科学自然基金(81371483);国家科学自然基金(81430089)~~
【分类号】：R114

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