Uptake and release of 3H-metaraminol by rat lung. The influence of various drugs.

Uptake and release of 3H-metaraminol was measured in vitro incubating rat lung tissue in the presence of ouabain (1.5-45 mug/ml), cocaine (1-30 mug/ml), tyramine (0.1-3 mug/ml, reserpine (0.05-1.5 mug/ml), imipramine (0.1-3 mug/ml) and desipramine (0.3-10 mug/ml. All drugs significantly inhibited uptake and release of 3H-metaraminol from lung tissue. This blockade most probably occurs at membrane levels of both neuronal uptake-1 sites and extraneuronal uptake-2 sites. These results further emphasize the importance of the lung in the fate of drugs and endogenous substances.