Concentration of dopamine analogs in the adrenal medulla.

Seven labeled sulfonanilide analogs of dipamine were synthesized and their tissue distribution in rats were determined as a function of time. The methanesulfonanilide derivative, NP-27, showed significant uptake and retention in the rat adrenal, with 0.66% dose/gm at 5 min and 0.27% dose/gm at 24 h. The 24-hr target-to-nontarget concentration ratios for the adrenal versus liver, blood, kidney, and heart were 13, 27, 30, and 60, respectively. These results compared reasonably with the corresponding target-to-nontarget ratios of 23, 45, 8, and 15 obtained for 14C-dopamine. The six other analogs showed considerably less uptake and retention. Further evaluation of NP-27 in dogs indicated selective uptake in the adrenal medulla.