title: Leukotriene A4-hydrolase activity in guinea pig and human liver.
abstract: Guinea pig and human liver homogenates transformed leukotriene A4 into leukotriene B4. In both species, the enzymatic activity was recovered in the 105000 X g supernatant, and it was found to be susceptible to heat treatment (56 degrees C, 1 h). Digestion with a proteolytic enzyme also resulted in loss of enzymatic activity. The formation of leukotriene B4 was pH-dependent, with an optimum between pH 7 and pH 8.5. In addition, two other organs from the guinea-pig, lungs and kidneys, contained leukotriene A4-hydrolase activity. The identity of leukotriene B4 was ascertained by high-performance liquid chromatography, ultraviolet spectrometry, gas chromatography-mass spectrometry and bioassay. We have recently demonstrated the presence of leukotriene A4-hydrolase activity in mammalian plasma (Fitzpatrick et al. (1983) Proc. Natl. Acad. Sci. USA 80, 5425-5429). The results of the present study suggest several possible origins of this plasma leukotriene A4 hydrolase.
authors.forename: J
authors.initials: J
authors.lastname: Haeggström
authors.forename: O
authors.initials: O
authors.lastname: Rådmark
authors.forename: F A
authors.initials: FA
authors.lastname: Fitzpatrick
mesh_terms: D000818:Animals; D001095:Arachidonic Acids; D002851:Chromatography, High Pressure Liquid; D004851:Epoxide Hydrolases / Q000302:isolation & purification / Q000378:metabolism*; D005260:Female; D006168:Guinea Pigs; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D017572:Leukotriene A4; D008099:Liver / Q000201:enzymology*; D008297:Male; D013347:Subcellular Fractions / Q000201:enzymology
chemical_list: D001095:Arachidonic Acids; D017572:Leukotriene A4; D004851:Epoxide Hydrolases; C043134:leukotriene A4 hydrolase