Insufflated red cells protect lungs from hyperoxic damage: role of red cell glutathione in scavenging toxic O2 radicals.

Hyperoxia-mediated pulmonary damage may involve formation of toxic oxygen species such as superoxide, hydrogen peroxide, and hydroxyl radical. Intact red cells evidently scavenge these when insufflated in small numbers into the tracheobronchial tree of rats. Such manipulation protects hyperoxic rats for prolonged periods of time and preserves normal pulmonary histology. Of several potential oxygen metabolite scavengers, a role for red cell glutathione seems particularly likely. It has not escaped our attention that an ironic, and previously unsuspected, connotation of our results emerges: namely, that a small degree of spontaneous alveolar bleeding, which is not an uncommon feature in respiratory distress situations, may actually be beneficial to patients--particularly those ventilated with excessive inspired oxygen concentrations. If confirmatory studies from other laboratories are forthcoming, the tracheal insufflation of autologous red cells in ventilated patients might be considered in the future.