Ny. Choksi et al., 2-PHENYLAMINOADENOSINE STIMULATES DOPAMINE SYNTHESIS IN RAT FOREBRAININ-VITRO AND IN-VIVO VIA ADENOSINE A(2) RECEPTORS, Brain research, 761(1), 1997, pp. 151-155
The adenosine agonist 2-phenylaminoadenosine (PAD) stimulated tyrosine
hydroxylase activity in rat striatum in vitro. This effect was select
ively blocked by the A(2) antagonist 8-chlorostyrylcaffeine (CSC), sug
gesting an A(2) receptor-mediated mechanism. PAD also produced a corre
sponding increase in striatal adenylyl cyclase activity. Using an in v
ivo model that measures presynaptic effects of drugs at dopamine nerve
terminals, intracerebroventricular administration of PAD to rats stim
ulated tyrosine hydroxylase activity in striatum in a manner that was
selectively blocked by CSC. These results suggest that PAD stimulates
adenylyl cyclase and tyrosine hydroxylase activity, with a correspondi
ng increase in dopamine synthesis, by activation of presynaptic A(2)-t
ype receptors in mammalian forebrain. (C) 1997 Elsevier Science B.V.