Suppression of Virus-Induced Corneal Toxicity in Rabbits by Pretreatment with Nitrogen Mustard.

Abstract

When a large amount of Newcastle disease virus (NDV) is inoculated into the anterior chamber of the rabbit eye, there results a toxic reaction characterized by corneal opacity and characteristic microscopic lesions of corneal endothelium: rosettes and fusions. Since an extensive infiltration of leucocytes, particularly polymor-phonuclear leucocytes, into the ocular tissues and the aqueous humor is a constant feature in the above reaction, a possible role of leucocytes in the pathogenesis of the corneal reaction was studied by using nitrogen mustard (HN2), a known suppressor for leucocytes. Pretreatment of rabbits with two intravenous injections of HN2 partially suppressed the production of NDV-induced toxic reaction. In most animals this treatment suppressed the development of opacity and reduced markedly the extent of endothelial fusions. It did not inhibit the formation of endothelial rosettes. The decreased response to injected virus is neither a result of the suppression of circulating leucocytes nor of rapid inactivation of the virus in the aqueous humor. Treatment of rabbits with a single intravenous injection of HN2 4 days, 2 days, or immediately before the virus injection caused no demonstrable suppression of the virus-induced toxic reaction of rabbit corneas. Leucocytes appeared to play no essential role in the production of the corneal reaction.