Injury induced by chemical warfare agents: characterization and treatment of ocular tissues exposed to nitrogen mustard.

Abstract

PURPOSE:

Mustard agents are highly toxic and abundant warfare chemicals, primarily affecting ocular tissues, with no specific treatment antidote. The purpose of the present study was to examine the efficacy of novel metallocomplexes, known to inhibit the formation of highly reactive free radicals, to reduce ocular injury induced by nitrogen mustard (NM).

METHODS:

One eye in each of 72 rabbits was exposed to 1% to 2% NM. Topical treatment with eye drops of a metallocomplex--either zinc- or gallium-desferrioxamine (Zn/DFO and Ga/DFO)--was compared with treatment with saline, zinc (chloride), or DFO alone. Examiners masked to the treatment groups assessed the extent of ocular injury and the response to treatment using clinical, histologic, and biochemical criteria.

RESULTS:

Exposure to NM followed by administration of carrier alone (saline) caused severe and long-lasting injury to ocular anterior segment structures. Treatment with either Zn/DFO or Ga/DFO yielded marked protection (52%-64%), including faster healing of corneal epithelial erosions, less scarring and neovascularization, decreased inflammation in the anterior chamber, better maintenance of intraocular pressure, and less severe changes in the iris and lens. These were also associated with better preservation of systemic antioxidant status. Zinc or DFO alone afforded lower levels of protection. No toxic effects of these complexes were observed.

CONCLUSIONS:

It is suggested that Zn/DFO or Ga/DFO, by virtue of their enhanced ability to infiltrate cells and inhibit transition metal-dependent formation of free radicals through the combined push-pull mechanism, be considered as a basis for treatment of mustard injuries.

• Authors: Eyal Banin, Yair Morad, Eduard Berenshtein, Alexey Obolensky, Claudia Yahalom, Jacob Goldich, Fatih M Adibelli, Gladys Zuniga, Maribel DeAnda, Jacob Pe'er, Mordechai Chevion
• Journal: Investigative ophthalmology & visual science (Invest Ophthalmol Vis Sci) Vol. 44 Issue 7 Pg. 2966-72 (Jul 2003) ISSN: 0146-0404 [Print] United States
• PMID: 12824239 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Chemical Warfare Agents
• Free Radicals
• Organometallic Compounds
• Reactive Oxygen Species
• Zinc Compounds
• Mechlorethamine
• Gallium
• Deferoxamine

Topics

• Administration, Topical
• Animals
• Anterior Eye Segment (drug effects, pathology)
• Burns, Chemical (drug therapy, pathology)
• Chemical Warfare Agents (toxicity)
• Deferoxamine (administration & dosage, therapeutic use)
• Electroretinography
• Eye Burns (chemically induced, pathology)
• Free Radicals (metabolism)
• Gallium
• Intraocular Pressure
• Mechlorethamine (toxicity)
• Organometallic Compounds (administration & dosage, therapeutic use)
• Rabbits
• Reactive Oxygen Species (metabolism)
• Wound Healing (drug effects)
• Zinc Compounds (administration & dosage, therapeutic use)