Induction of ocular inflammation by synthetic mediators
A. Ben-Zvi, M. M. Rodrigues, I. Gery and E. Schiffmann
Chemotactic mediators, N-formylmethionyl-leucyl-phenylalanine (FMLP) and
the complement component C5a, were injected into the rabbit cornea,
vitreous, and skin to induce a reaction resembling the "Arthus phenomenon."
Injection of these mediators induced edema and granulocytic infiltration in
the cornea, conjunctiva, and skin. These histologic changes resembled the
inflammation produced by antigen (ovalbumin [OVA]) in specifically
immunized rabbits. Keratitis began after two hours and subsided six hours
after the injection. Conversely, the vitreous response started six hours
after injection of FMLP and C5a and peaked between 24 and 48 hours. All the
inflammatory reactions induced by FMLP, C5a, and rechallenge with antigen
could be inhibited in varying degrees by subconjunctival injection of 0.1
mL of 10(-5)M dexamethasone, quinacrine, 5,8,11,14-eicosatetraynoic acid
(ETYA), or indomethacin, agents that suppress different sites of chemotaxis
of polymorphonuclear leukocytes. However, only the inflammation induced by
FMLP could be inhibited by carbobenzoxy-phe-met, a competitive inhibitor of
FMLP.
