A simple biological way to screen dopaminergic agonists.

The velocity of propagation of the in vitro retinal model of spreading depression is very sensitive to changes in the ionic composition of the extracellular medium and also to the the addition of different drugs. 10 microM of SKF 38393, a D1 agonist, increases the velocity of propagation of the wave while 10 microM of Quinpirole, a D2 agonist, decreases it. Both changes are blocked by their specific antagonists, SCH23390 and 1-sulpiride respectively. This assay can biologically screen potential dopaminergic drugs indicating its physiological D1 and/or D2 preferred effect in the tissue for future analysis by other different methodologies.