PROTECTIVE INFLUENCE OF ANTIOXIDANTS ON PULMONARY VASCULAR-PERMEABILITY IN A STRESS MODEL

Sympathetic nerve stimulation as a model for stress increases the filt ration of protein-rich fluid from the pulmonary vasculature into the l ung parenchyma. Oxidative biochemical processes may lead to the develo pment of increased permeability. The purpose of this study was to dete rmine whether prior administration of a combination of several dietary antioxidants (alpha-tocopherol, beta carotene, and ascorbic acid) wou ld attenuate this sympathetic-induced increase in permeability. In the excised rabbit lung, the capillary filtration coefficient (Kfc) incre ased from 0.58 +/- 0.06 mL min(-1) mm(-1) Hg/100 g lung weight in norm al controls to 1.89 +/- 0.30, p < 0.001 in rabbits exposed to sympathe tic nerve stimulation. The Kfc following antioxidant administration an d sympathetic nerve stimulation was 0.62 +/- 0.54. This evidence sugge sts that antioxidants can protect against the pulmonary vascular perme ability changes which occur with acute stress as represented by sympat hetic nerve stimulation.