Contribution of beta-adrenoceptors to the dopamine-induced elevation of cyclic 3',5'-adenosine monophosphate levels in mouse lymphocytes.

The receptors involved in the cyclic adenosine 3',5'-monophosphate (cAMP)-increasing action of dopamine (DA) in mouse lymphoid cells were determined by comparing the potencies of specific DA receptor and adrenoceptor antagonists to inhibit the cAMP response to DA and to isoproterenol. The beta-adrenoceptor antagonists propranolol, pindolol and dichloroisoproterenol were the most potent inhibitors of the response to both DA and isoproterenol. Their potencies were 2-3 orders greater for the inhibition of DA than isoproterenol action. SCH 23390 (selective DA1 antagonist) and haloperidol (mixed DA1/DA2 antagonist) inhibited the DA action only at high concentrations (10(-5)-10(-4) M) which did not affect the response to isoproterenol. These results indicate that beta-adrenoceptors are involved in the DA-induced elevation of mouse lymphocyte cAMP.