Inflammation may serve as one of the principal initiators of acute and chronic lung diseases in man. Inflammatory hormones are transiently released into the blood at very low concentrations. Because of their extremely low concentrations, lability and destruction within blood and surrounding tissues, detection and quantitation in vivo is difficult. Using a novel method of perfusion of a negative pressure ventilated rat or guinea pig lung, the concentration of vasoactive hormones present in the lung effluent is determined by isotonic concentrations of a series of smooth muscle bioassay systems. Kinetic measurements of the production of prostaglandins will be undertaken as well as other inflammatory hormones, and the effect of the oxidizing air pollutants, ozone and nitrogen dioxide, will be determined. Levels of air pollution of industrial and environmental exposure will be used to estimate the effects of air pollutants on vasoactive hormone release, biosynthesis and metabolism by the lung. These studies will provide quantitative estimates of the release of inflammatory hormones by the lung and may lead to a better understanding of inflammation in inhalation toxicology in man. BIBLIOGRAPHIC REFERENCES: Heinz Bodies Formed in Erythrocytes by Fatty Acid Ozonides. D.B. Menzel, R.J. Slaughter, A.M. Bryant and H.O. Jauregui. Arch. Environ. Health 30, 296-301 (1975); Prevention of Ozonide-Induced Heinz Bodies in Human Erythrocytes by Vitamin E. D. B. Menzel, R.J. Slaughter, A.M. Bryant and H.O. Jauregui. Arch. Environ. Health 30, 234-236 (1975).