[The regulating effects of dopamine receptors on the level of adenosine 3, 5-cyclic monophosphate in bovine trabecular cells in vitro].

OBJECTIVE

To assay the regulating effects of dopaminergic agonists and antagonists on adenosine 3, 5-cyclic monophosphate (cAMP) level in bovine trabecular cells (BTC) in vitro.

METHOD

H(3)-cAMP was used in protein binding assay to determine the level of cAMP in bovine BTC.

RESULTS

Dopamine, a dopamine receptor agonist, and fenoldopam, a selective DA(1) receptor agonist, caused a fold increase of cAMP in cultured BTC in vitro. These effects were blocked by halporide, a non-selective dopamine antagonist, and SCH23309, a selective DA(1) antagonist, but not blocked by phenoxybenzamin, an alpha-adrenergic antagonist, and timolol, a beta-adrenergic antagonist.

CONCLUSION

Bovine trabecular cells contain not only beta-receptors but also DA(1) receptors.