LTB3 is the LTA hydrolase metabolite of LTA3 in the leukotriene biosynthetic pathway. LTB3 and LTB4 are equipotent in their pro-inflammatory effects. However, LTB3 is five times less potent than LTB4 in eliciting chemotaxis of human neutrophils.
Thromboxane B3 (TXB3), the stable hydrolysis product of TXA3, is synthesized from eicosapentaenoic acid (EPA) through the action of COX and thromboxane synthase enzymes. This compound is biosynthesized in several tissues, including seminal vesicles, lungs, polymorphonuclear leukocytes (PMNL), and ocular tissues.