Tissue distribution of leukotriene A4 hydrolase activity in guinea pig

The distribution of the activity of leukotriene A4 hydrolase, an enzyme catalyzing hydrolysis of the allylic epoxide leukotriene A4 to the dihydroxy acid leukotriene B4, was determined in various tissues of guinea pig by using the supernatant fraction (100,000 X g, 60 min) of the homogenates. The activity was ubiquitously distributed in all tissues examined, and the highest specific activity was found in small intestine, followed by lung, aorta, colon, and spleen, in this order. The specific activity in these tissues was higher than that of leukocytes. The physiological roles of this compound in these organs deserve reexamination in this context.