EFFECT OF CYTOCHROME-P450 ARACHIDONATE METABOLITES ON ION-TRANSPORT IN RABBIT KIDNEY LOOP OF HENLE

In the medullary segment of the thick ascending limb of the loop of Henle (mTALH), arachidonic acid (AA) is metabolized by a cytochrome P450-dependent monooxygenase to products that affect ion transport. The linkage between changes in ion transport and AA metabolism in isolated cells of the mTALH was examined. AA produced a concentration-dependent inhibition of Rb-86 uptake - an effect that was prevented by selective blockade of cytochrome P450 monooxygenases. Inhibition by cytochrome P450 blockade of the effect of AA on Rb-86 uptake could be circumvented by addition of the principal products of AA metabolism in the mTALH.