EFFECTS OF KAMIKIHITO, A TRADITIONAL CHINESE MEDICINE, ON NEUROTRANSMITTER RECEPTOR-BINDING IN THE AGED RAT-BRAIN DETERMINED BY IN-VITRO AUTORADIOGRAPHY .1. CHANGES IN THE [H-3] QNB BINDING

Using in vitro autoradiography, we investigated the effects of Kamikih ito (KKT), a traditional Chinese medicine, on the specific binding of H-3quinuclidinyl benzilate (QNB) and H-3N-(1-2-thienylcyclohexyl )-3,4-piperidine (TCP) in the rat brain. The B-max but not the K-d val ues for H-3QNB binding to the caudate/putamen and accumbens in aged rats were lower than those in young rats. The H-3TCP binding was als o decreased in aged rats compared with that in young rats. Long-term a dministration of KKT modulated the H-3QNB binding in young but not a ged rats.