LECITHINIZED SUPEROXIDE-DISMUTASE ATTENUATES PHORBOL-MYRISTATE ACETATE-INDUCED INJURY IN ISOLATED DOG LUNG

Lecithinized superoxide dismutase, a lecithin derivative bound to reco mbinant human CuZn superoxide dismutase, has a higher affinity for cel ls such as polymorphonuclear leukocytes and endothelial cells than rec ombinant human CuZn superoxide dismutase has. We determined the protec tive effects of lecithinized superoxide dismutase on the increased mic rovascular permeability induced by phorbol myristate acetate (PMA) in isolated dog lungs. Microvascular permeability was assessed by the cap illary filtration coefficient (K-f,K-c) and solvent drag reflection co efficient (sigma(f)). PMA (13.3 mu g) increased microvascular permeabi lity, as evidenced by an increase in K-f,K-c and the small sigma(f) va lue. Lecithinized superoxide dismutase at both low (4800 U) and high d oses (48000 U) inhibited the PMA-induced increase in K-f,K-c, but only the high dose of lecithinized superoxide dismutase attenuated the dec rease in sigma(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 (48000 U). These findings suggest that lec ithinized superoxide dismutase has a protective effect against oxygen radical-induced lung injury in isolated dogs lungs. (C) 1998 Elsevier Science B.V.