Characterization of arachidonic acid metabolism and the polymorphonuclear leukocyte response in mice infected intracorneally with Pseudomonas aeruginosa.
OBJECTIVE
To examine the activity of myeloperoxidase (MPO) and the concentrations of the proinflammatory metabolites of arachidonic acid (AA) in ocular tissue of mice that are either capable or incapable of restoring corneal clarity during an intraocular Pseudomonas aeruginosa infection.


METHODS
For a period of 11 days after infection, whole eyes were enucleated and homogenized in buffer from mice given only an initial infection as well as from mice given a subsequent infection in the previously uninfected eye either 4 or 8 weeks after the initial infection. Tissue-free supernatants from the ocular homogenates were used for the determination of MPO activity by quantitating the conversion of specific substrate by spectrophotometric methods and for the quantitation of AA metabolites by ELISA:


RESULTS
Overall, animals reinfected at 4 and 8 weeks had a lower inflammatory response when compared to the mice given only the initial infection. The lowest levels of LTB4 and MPO activity, indicators of PMN involvement, were observed in the the 8-week reinfected mice, which restored corneal clarity in an enhanced manner.


CONCLUSIONS
These results suggest that induced ocular PMN responses may play a role, in part, in the inflammatory response leading to the tissue destruction observed during ocular P. aeruginosa infection.
Kernacki
K A
KA
Department of Immunology/Microbiology, Wayne State University School of Medicine, Detroit, Michigan 48201.
Berk
R S
RS
D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism*; D003315:Cornea / Q000737:chemistry / Q000378:metabolism* / Q000382:microbiology; D015232:Dinoprostone / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D015818:Eye Infections, Bacterial / Q000378:metabolism*; D005260:Female; D007634:Keratitis / Q000378:metabolism* / Q000382:microbiology; D007958:Leukocyte Count; D007975:Leukotriene B4 / Q000032:analysis; D051379:Mice; D008810:Mice, Inbred C57BL; D009504:Neutrophils / Q000378:metabolism*; D009195:Peroxidase / Q000378:metabolism; D011552:Pseudomonas Infections / Q000378:metabolism*; D013929:Thromboxane B2 / Q000032:analysis
D007975:Leukotriene B4; D016718:Arachidonic Acid; D013929:Thromboxane B2; D009195:Peroxidase; D015232:Dinoprostone