ABSENCE OF METABOLISM OF MORPHINE DURING ACCUMULATION BY ISOLATED PERFUSED RABBIT LUNG

  • 1 January 1979
    • journal article
    • research article
    • Vol. 7  (6) , 425-428
Abstract
Pulmonary accumulation and metabolism of morphine was studied in an isolated perfused lung system. No metabolism of morphine or N-demethylation of ethylmorphine was found. Accumulation from the recirculating perfusate was nonsaturable over a concentration range of 3-400 .mu.M morphine. Inhibition of Na transport or Na depletion decreased morphine accumulation. The results are most consistent with passive diffusion of morphine down an electrochemical gradient and subsequent nonspecific binding to tissue anions. Normal movement of Na and K is required to maintain this gradient.