Effects of taclamine (AY-22,214), a new psychoactive agent, on catecholamine and serotonin metabolism

The effects of a new psychopharmacologically-active agent taclamine (AY-22,214 (AY)(a dibenzocycloheptaisoquinolines)) on noradrenaline (NA), dopamine (DA) and serotonin(5-HT) turnover in the brains of normal and/or stressed animals were determined by the use of both non-isotopic and isotopic techniques; a comparison with chlordiazepoxide (CL) was carried out. Both AY and CL antagonized the increase in NA and 3H-NA turnover due to immobilization stress in whole, and selected regions, of the rat brain. AY, unlike CL did not decrease 3H-NA turnover in brains of non-stressed animals. AY accelerated the turnover of DA in whole brain and 3H-DA in the striatum. In contrast, CL decreased turnover of each. AY did not alter 5-HT turnover. CL decreased 14C-5-HT turnover in regions of rat brain; in addition, it antagonized the pargyline-induced rise in 5-HT and potentiated the subsequent fall in levels of 5-HIAA. Neither AY nor CL affected the 5-HT uptake in the mouse brain. It is concluded that AY appears to exhibit both similarities and differences to CL with regard to its effects on biogenic amine turnover.