The effect of drugs stimulating central dopaminergic system on transformation of exogenous adenine into c-AMP.

We tested the effect of dopamine (DA), apomorphine (APM), amantadine (AMD), dimethylaminoadamantane (DMAD) or haloperidol (HP) on the in vitro formation of c-AMP from ATP labelled intracellularly with exogenous 14C-adenine or from endogenous ATP in the slices of rat striatum. DA stimulated the synthesis of c-AMP from endogenous and 14C-adenine labelled ATP. Nonspecific stimulants of the dopaminergic system, APM, AMD and DMAD, stimulated the c-AMP synthesis much weaker than DA did. After application of APM, ADM or DMAD, the utilization of ATP formed from 14C/U/adenine for synthesis of c-AMP was lower than after DA. The effects of combined treatment with DA together with APM, AMD or DMAD was additive. HP, 1 X 10(-3) M did not change the amount of radioactive and total c-AMP, but inhibited the stimulatory action of DA and, to a lesser degree, of APM, AMD and DMAD. The synthesis of c-AMP from endogenous ATP stimulated with APM, AMD and DMAD in striate body slices was inhibited by HP more strongly than the synthesis of c-AMP from ATP labelled with exogenous 14C-adenine. The results indicate that ATP synthesized from intracellular adenyl nucleotides is more effectively utilized for the synthesis of c-AMP stimulated by APM, AMD or DMAD in striate body slices, than ATP labelled with 14C-adenine.