Effects of Kamikihito, a Traditional Chinese Medicine, on Neurotransmitter Receptor Binding in the Aged Rat Brain Determined by In Vitro Autoradiography (2): Changes in GABAA and Benzodiazepine Receptor Binding

[摘要] References(20)Cited-By(6)We investigated the effects of the long-term administration of Kamikihito (KKT) on the specific binding of [3H]muscimol and [3H]flunitrazepam in the brains of young and aged rats using in vitro quantitative autoradiography. Specific [3H]muscimol binding in aged rats was decreased in all brain regions examined compared with that in young rats, whereas [3H]flunitrazepam binding did not change in any of the brain regions. Scatchard analysis revealed that the maximal number of [3H]muscimol binding sites in the cortex and thalamus was significantly decreased in aged rats compared with young rats, while its affinity remained unchanged. Long-term administration of KKT in young rats had no effect on either [3H]muscimol or [3H]-flunitrazepam binding. In contrast, the same treatment in aged rats produced a significant increase in [3H]-flunitrazepam binding to the cortex, caudate/putamen and accumbens, and it tended to decrease the [3H]-muscimol binding. These results suggest that the selective reduction of specific [3H]muscimol binding in the brain may be responsible, at least in part, for anxiety-related behavior in aged rats. Furthermore, it appears that the significant increase in specific [3H]flunitrazepam binding produced in the brains of aged rats by the long-term administration of KKT may be responsible for the anxiolytic effects of this agent.

[学科分类] 药理学

[关键词] Kamikihito;Aged rat;[3H]Muscimol binding;[3H]Flunitrazepam binding;Autoradiography