thromboxane-b2 and Keratitis

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.. 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:. 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.. 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.

Topics: Animals; Arachidonic Acid; Cornea; Dinoprostone; Enzyme-Linked Immunosorbent Assay; Eye Infections, Bacterial; Female; Keratitis; Leukocyte Count; Leukotriene B4; Mice; Mice, Inbred C57BL; Neutrophils; Peroxidase; Pseudomonas Infections; Thromboxane B2

In order to characterize the inflammatory response to corneal infection by Pseudomonas aeruginosa, ocular cytokine and arachidonic acid metabolite levels were determined in the C57BL/6J strain of mice. The effects of topical anti-inflammatory drugs on the ability of the mice to clear viable P. aeruginosa from the eyes during the 12 day infection period was also examined. Ocular IL-1 alpha, IL-6, and TNF-alpha were detected over an 11 day time period. Little or no bacteria, as determined by quantitative plate counts, was detected after this time period. The kinetics of the cytokine production varied from one another, with an immediate release of peak levels of IL-1 alpha within 24 hours after infection which did not begin to approach baseline until 9 to 11 days after infection. Five to ten-fold lower concentrations of IL-6 and TNF-alpha were detected. IL-6 levels were induced at 24 hours after infection but there was essentially no distinct peak time-point. Peak levels of TNF-alpha were detected at 6 days post-infection. The kinetics of arachidonic acid metabolite release from infected eyes were also examined. Peak levels of PGE2 and TxB2 were observed at 6 days post-infection whereas peak LTB4 levels were determined at 3 days post-infection. Topical treatment of infected eyes with the two anti-inflammatory drugs, prednisolone or quercetin, resulted in higher ocular bacterial levels throughout the infection.

Topics: Animals; Colony Count, Microbial; Cytokines; Dinoprostone; Eye Infections, Bacterial; Keratitis; Mice; Mice, Inbred C57BL; Ophthalmic Solutions; Prednisolone; Pseudomonas aeruginosa; Pseudomonas Infections; Quercetin; Thromboxane B2