Lecithinized superoxide dismutase attenuates phorbol myristate acetate-induced injury in isolated dog lung

Abstract Lecithinized superoxide dismutase, a lecithin derivative bound to recombinant human CuZn superoxide dismutase, has a higher affinity for cells such as polymorphonuclear leukocytes and endothelial cells than recombinant human CuZn superoxide dismutase has. We determined the protective effects of lecithinized superoxide dismutase on the increased microvascular permeability induced by phorbol myristate acetate (PMA) in isolated dog lungs. Microvascular permeability was assessed by the capillary filtration coefficient ( K f,c ) and solvent drag reflection coefficient ( σ f ). PMA (13.3 μ g) increased microvascular permeability, as evidenced by an increase in K f,c and the small σ f value. Lecithinized superoxide dismutase at both low (4800 U) and high doses (48 000 U) inhibited the PMA-induced increase in K f,c , but only the high dose of lecithinized superoxide dismutase attenuated the decrease in σ f . Recombinant human CuZn superoxide dismutase did not affect the PMA-induced increase in vascular permeability at either a low (4800 U) or a high dose (48 000 U). These findings suggest that lecithinized superoxide dismutase has a protective effect against oxygen radical-induced lung injury in isolated dog lungs.