Electrolyte and fluid transport in the kidney are regulated in part by arachidonic acid and its metabolites. 16-HETE is a minor CYP450 metabolite of arachidonic acid released by the kidney upon angiotensin II stimulation that demonstrates stereospecific biological activity. Electrolyte and fluid transport in the kidney are regulated in part by arachidonic acid and its metabolites. 16-HETE is a minor CYP450 metabolite of arachidonic acid released by the kidney upon angiotensin II stimulation that demonstrates stereospecific biological activity. 16(R)-HETE inhibits proximal tubule ATPase activity by as much as 60% at a concentration of 2 µM.{3825}