短期饥饿对老年、成年大鼠下丘脑加压素神经元及血浆皮质酮的影响

免疫组化光、电镜法观察禁食五天老年及成年大鼠下丘脑精氨酸加压素(AVP)神经元,并检测其血浆皮质酮(B),与同龄正常鼠相比.结果:(1)B均值明显升高(P<0.01),(2)各神经核团的阳性神经元有增有减,非同步变化,(3)正中隆起外带阳性纤维密集,面积增加,(4)视上核主部及室旁核的神经元粗面内质网层次增多,线粒体较密集,(5)成年饥饿鼠阳性细胞总数增加,但其视上核主部的减少,并和血浆B的增加负相关(r=-0.98,P<0.01),而老年饥饿鼠阳性细胞总数减少,且和血浆B的相关性不明显.实验结果表明:血浆B和下丘脑AVP神经元均有明显应激反应,不论成年或老年鼠对短期饥饿均呈现合成及分泌AVP较旺盛的结构变化,但老年的饥饿应激反应弱于成年鼠的.

CHANGES OF ARGININE VASOPRESSIN NEURONS OF HYPOTHALAMUS AND PLASMA CORTICOSTERONE IN ADULT AND OLD RATS FOLLOWINGS SHORT-TERM STARVATION

This study was designed to analyse the changes of arginine vasopressin (AVP) neurons of hypothalamus,and to assay the level of plasma corticosterone in adult and old rats following 5 days of starvation by immunohistochemical light and electronic microscopy.The results revealed that:(1) plasma corticosterone level elevated significantly in adult starved rats;(2) the number of AVP-positive neurons increased in some neural nuclei but declined in others;(3) denser color and larger area immunoreactive fibers were observed in the lateral zone of the median eminence in adult starved rats;(4) the increase in the numer of rough endoplasmic reticula and mitochondria was also observed in adult starved rats;(5) the number of AVP-positive neurons declined while plasma corticosterone level elevated,showing significant negative relation (r=-0.98,P<0.01).The results demonstrated that the changes of AVP neurons in hypothalamus and plasma corticosterone level brought about significant stress response.After starvation AVP neurons in hypothalamus showed the characteristics of active proteins synthesis.Stress response was less in old rats than the adult rats following short-term starvation.