ABSTRACT
The ability of rabbit conjunctiva and anterior uvea to synthesize lipoxygenase products was assessed. Using autoradiographic techniques, we demonstrate that rabbit anterior uvea synthesizes 5 and 12 lipoxygenase products such as 12-HETE, 5-HETE and 5,12-DiHETE and cyclooxygenase product HHT from 14C-arachidonic acid. Indomethacin pretreated conjunctiva and anterior uvea generated slow reacting substance (SRS)-like activity from arachidonic acid in the presence of reduced glutathione and A23187. This SRS-like activity contracted guinea pig ileum. Specific SRS-like activity antagonist FPL-55712 inhibited the contractions of guinea pig ileum induced by SRS-like substance generated by either conjunctiva or anterior uvea. The activity was still present in the sample following extraction with organic solvents. SRS-like activity was destroyed by arylsulfatase and its generation was prevented by either boiling or pretreatment with cyclooxygenase/lipoxygenase inhibitors, BW755 and nordihydroguaiacetic acid. These results indicate that following cyclooxygenase inhibition by indomethacin rabbit conjunctiva and anterior uvea generate SRS-like activity from arachidonic acid via lipoxygenase pathways.