Antibodies against rabbit omega-hydroxylases of prostaglandins and fatty acids cross-react with leukotriene B4 omega-hydroxylase in human neutrophils (cytochrome P-450LTB omega).

Leukotriene B4 (LTB4) omega-hydroxylase activity in human neutrophil microsomes was significantly inhibited by antisera against three rabbit omega-hydroxylase P-450s, lung prostaglandin omega-hydroxylase (P-450p-2), small intestine prostaglandin A omega-hydroxylase (P-450ia), and kidney fatty acid omega-hydroxylase (P-450kd). In contrast, the activity is not affected by antibodies raised against the phenobarbital-inducible forms of P-450s from both rabbits and rats. These findings suggest that the LTB4 omega-hydroxylase (P-450LTB omega) is structurally related to a group of rabbit omega-hydroxylase P-450s. The antiserum raised against P-450p-2 also inhibited the NADPH-dependent oxidation of 20-hydroxy LTB4 to 20-oxo LTB4 and 20-carboxy LTB4 by the microsomes, supporting that P-450LTB omega is able to catalyze the subsequent oxidation of 20-hydroxy LTB4 as well as the omega-hydroxylation of LTB4.