松果体褪黑素对大鼠下丘脑CRH神经元的影响

Effect of Pineal Gland and Melatonin on CRH Neuron of Rat Hypothalamus

目的研究松果体和褪黑素对大鼠下丘脑室旁核促肾上腺皮质激素释放激素(CRH)神经元形态和功能的影响以及补充褪黑素的作用。方法雄性清洁级SD大鼠100只,随机分为对照组、假手术对照组、松果体摘除组、松果体摘除+褪黑素腹腔注射7.5mg/kg组和松果体摘除+褪黑素腹腔注射15mg/kg组,采用原位杂交和免疫组织化学方法来检测松果体摘除及补充褪黑素后下丘脑CRH神经元的变化。结果松果体摘除后大鼠下丘脑室旁核CRH表达增强。松果体摘除大鼠补充褪黑素后,CRH神经元表达增强呈剂量依赖性恢复,但不能恢复至正常。结论松果体摘除导致大鼠下丘脑室旁核CRH神经元合成CRH增加,补充外源性褪黑素后能在一定程度上逆转上述异常。松果体可能是神经-内分泌-免疫网络的结构和功能的重要稳定因素之一。

Objective To study the morphological and funetional effects of pinealectomy（PX） and melatonin on CRH neurons in paraventricular nucleus of rat hypothalamus as well as the function of melatonin supplementation. Methods 100 male SD rats were randomly divided into five groups. In situ hybridization（ISH） and immunohistochemistry（IHC） were used to observe the changes of hypothalamic CRH positive cells PX and melatonin and melatonin supplementation. Results Compared to sham group, ISH and IHC conducted for examing rat＇s hypothalamic CRH showed the expression of hypothalamic CRH neurons enhanced after PX. With the enhancement of hypothalamic CRH appearing in the rats given pineal grand and melatonin after melatonin supplementation, their dependance on dose recoverd,but could not return to the normal state either in high dose group or in low dose group and either at 4th week or at 8th week. Conclusion PX enhanting synthesis and release of CRH with the increase of CRH neurons, and activates HPA axis through hypophyseal portal system. However, melatonin supplementation can partly reverse the abnormality, which indicates pineal body is one of the key factors to maintain the structural and functional stablity of neuroendocrine-immune network.