大鼠脑中5—羟色胺受体的检定及其在衰老时的变化

采用放射性配基结合分析法,对大鼠大脑皮质的5-HT受体作了检定,并观察了老年大鼠(36月龄)大脑皮质中该受体的变化。证实大鼠大脑皮质存在着丰富的、高亲和力和单一结合位点的5-HT受体。老年大鼠大脑皮质中5-HT受体的数目较成年大鼠(3月龄)明显减少,但亲和力无改变。应用荧光分光技术测定了成年和老年大鼠脑干和大脑皮质5-HT含量,证实老年大鼠上述两个脑区的5-HT含量均有降低。本研究的结果提示,老年大鼠中枢5-HT系统的功能减低,这一变化可能与老年期的一些表现如睡眠障碍、体温低、记忆力减退和易患精神疾病等有关。

CHARACTERIZATION OF SEROTONIN RECEPTOR IN RAT BRAIN AND ITS CHANGE IN SENESCENT RATS

By means of radioligand binding assay, the serotonin (5-HT) receptor was identified in the cerebral cortex of rats, and the change in cerebral 5-HT receptor in senescent rats was observed. The results demonstrated that abundant 5-HT receptors with high 'affinity existed in membranes prepared from cerebral cortex of rats, and maximal binding capacity (Bmax) of 5-HT receptors in cortex of senescent rats (36 months) markedly decreased as compared with that of the mature rats (3 months), but no significant difference in the Kd value was found. The contents of 5-HT in brain stem and cerebral cortex of rats were measured by spectrofluorimetric technique. It was confirmed that 5-HT contents in brain stem and cerebral cortex of senescent rat were significantly lower than those of mature rats. The results suggested that the central serotonergic system in senescent rats was insufficient to maintain the normal physiological functions. The change described above may be related with the characteristics of the aged, such as dyssomnia, high incidence of affective illness, low body temperature and hypomnesia.