title: Phospholipid bilayers enhance the stability of leukotriene A4 and epoxytetraenes: stabilization of eicosanoids by liposomes.
abstract: The hydrolysis of leukotriene A4 and two epoxytetraenes was examined in the presence and absence of liposomes. When added to liposomes in suspension, the stability of LTA4 was increased in a time- and dose-dependent fashion. At 10 min, the half-life of LTA4 was increased 67.1 +/- 6.8% in the presence of liposomes which was comparable to that observed with albumin (10 mg/ml): 68.3 +/- 6.9%. Phosphatidylcholine, in a non-bilayer configuration, was also effective in enhancing the half-life of LTA4, albeit to a lesser extent than liposomes. At equal molar concentrations, the enhanced stability of eicosanoid epoxides with liposomes gave a rank order with leukotriene A4 greater than 5(6)epoxytetraene greater than 14(15)epoxytetraene. Results indicate that phospholipid bilayers can protect leukotriene A4 and 5(6)epoxytetraene from non-enzymatic hydrolysis. Moreover, they suggest that the biological half-life of intermediates involved in the formation of both leukotrienes and lipoxins can be increased by their association with membranes.
authors.affiliation: Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115.
authors.forename: S
authors.initials: S
authors.lastname: Fiore
authors.forename: C N
authors.initials: CN
authors.lastname: Serhan
mesh_terms: D000418:Albumins; D004355:Drug Stability; D015118:Eicosapentaenoic Acid; D006207:Half-Life; D006801:Humans; D017572:Leukotriene A4; D015289:Leukotrienes; D008051:Lipid Bilayers; D008081:Liposomes; D010713:Phosphatidylcholines; D010743:Phospholipids
chemical_list: D000418:Albumins; D017572:Leukotriene A4; D015289:Leukotrienes; D008051:Lipid Bilayers; D008081:Liposomes; D010713:Phosphatidylcholines; D010743:Phospholipids; D015118:Eicosapentaenoic Acid