[Effect of tobramycin with topical diclofenac on arachidonic acid in endotoxin-induced uveitis]

We studied if tobramycin associated to sodium diclofenac modifies the drug effect of the latter on arachidonic acid metabolism in an endotoxin induced uveitis (EIU) model in albino rabbits.

Experimental uveitis was induced by intravitreal injection of a 10 ng lipopolysaccharide A Salmonella typhimurium endotoxin dissolved in 5 microl saline solution in the right eye of experimental animals. We have used 48 animals (4 groups of 12 animals each). The control group (G-I) was injected with saline solution (5 microl); the endotoxin group (G-II) was injected with 5 microl of ET; group III and IV were injected with the same amount of ET and treated with topical sodium diclofenac (1%) (Group III) and tobramycin and sodium diclofenac (0.3%) (Group IV) two hours before the administration of endotoxin and then every two hours until 24 hours, when we determined E2 prostaglandin and B4 leukotriene concentration in aqueous humor obtained by paracentesis of the anterior chamber.

We observed how the E2 prostaglandin concentration was reduced in the two treatment groups compared with the endotoxin group (p<0.01). However, there were no differences between groups III and IV (p>0.01). There was a mild increase of B4 leukotriene in both treatment groups, which was not significant in relationship to the endotoxin group (p>0.01). No differences were found between the two treatment groups (p>0.01).

Using the association of tobramycin does not affect the action of sodium diclofenac in arachidonic acid metabolism in endotoxin induced uveitis.