The effect of the specific alpha 2-adrenoceptor agonist BHT 933 on stimulated renin release was investigated in the isolated perfused rat kidney preparation. Renin release was stimulated with N-ethylcarboxamide adenosine (NECA) (3 microM) a specific A2-adenosine receptor agonist. alpha 2-Adrenoceptor stimulation with BHT 933 (1 microM) attenuated the stimulation of renin release by NECA. Yohimbine (300 nM) or prazosin (28 nM) at alpha 2- and alpha 1-adrenoceptor specific concentrations respectively, blocked this inhibition of renin release by BHT 933. In all groups studied there was no significant effect of these experimental treatments on renal hemodynamics or electrolyte excretion. The ability of yohimbine or prazosin, at alpha 2- and alpha 1-adrenoceptor specific concentrations respectively, to antagonize the effects of BHT 933 suggests a lack of agonist specificity for these receptor effect as previously suggested for the mesenteric artery.