EFFECT OF DIETARY ANTIOXIDANTS ON PULMONARY VASCULAR-PERMEABILITY FOLLOWING SYMPATHETIC-NERVE STIMULATION

As a model for stress, sympathetic nerve stimulation increases the fil tration of protein-rich fluid from the pulmonary vasculature into the lung parenchyma. Oxidative biochemical processes may lead to the devel opment of increased permeability. The purpose of our study was to dete rmine whether prior oral administration of a combination of common die tary antioxidants (alpha-tocopherol, beta carotene, and ascorbic acid) for 14 days in physiological amounts would attenuate a sympathetic-in duced increase in permeability. In the excised rabbit lung, the capill ary filtration coefficient (Kfc) increased from 0.34 +/- 0.07 ml/min/ mmHg/100 g lung weight in normal controls to 0.63 +/- 0.10, P < 0.001, in rabbits exposed to sympathetic nerve stimulation. The Kfc followin g antioxidant administration and sympathetic nerve stimulation was 0.3 1 +/- 0.02 Broncho-alveolar lavage (BAL) protein from controls was 1.4 +/- 0.23 mg/g lung, from stimulated rabbit lungs 8.3 +/- 8.3, and in rabbits given antioxidants plus stimulation, 0.8 +/- 0.29. This eviden ce suggests that orally administered antioxidants over 14 days can pro tect against the pulmonary vascular permeability changes which occur i n a model of acute stress. Med Sci Res 26:539-540 (C) 1998 Lippincott Williams & Wilkins.