【摘要】 整体脑Ｍ受体代谢动力学实验表明，老年小鼠脑Ｍ受体的生成和降解均慢于青年对照，前者减慢的程度超过后者，导致生成和降解速率的失平衡，从而使受体密度在降低水平上达到新的稳态，知母水提物长期口服同时促进脑Ｍ受体的合成和降解，对合成的加快作用更强，所以知母提高衰老时脑Ｍ受体密度的机制主要在促进受体分子的生成，从而纠正生成和降解的失平衡。离体实验中知母有效成分ＳＡＲ对脑Ｍ受体与３Ｈ－ＱＮＢ的结合无竞争作用，故知母的上述作用并非属于Ｍ受体拮抗剂的性质。更多还原

【Abstract】 AbstractThe study of the kinetic parameters of M-receptor metabolism showed that both theproduction rate and degradation rate of brain M-receptors in aged mice were slower thanyoung mice. The retardation of production was more prominant than that of degradation,indicating that the decrease of brain M-receptor density in aged mice was due to animbalance of the two rates. When aged mice were orally given aqueous extract of Zhimu for 3 months, the production and degradation of brain M-receptors were both acce lerated, with the former accelerated more prominantly. Therefore, the mechanism ofthe up-regulatory effect of Zhimu on brain M-receptor density is to speed up the production rate and to correct the imbalance of prodution and degradation of the receptormolecules. Competitive binding assay revealed that the active component of Zhimu didnot compete with 3H-QNB for the binding sites of brain M-receptors, hence it is not anantagonist of M-receptors.更多还原