Increase in atrial natriuretic factor in the lungs, heart, and circulatory system owing to ozone

Ozone can cause pulmonary edema and simultaneously decrease blood pressure. Atrial natriuretic factor (ANF) may mediate both of these effects in that it increases pulmonary capillary permeability resulting in edema formation and vasodilates the vascular system. The present investigation was designed to test directly the effect of ozone on the content of ANF in the lungs, heart, and the circulatory system. Ozone (0.5 ppm) exposure for 8 h increased ANF content in the lungs fourfold (13.33 +/- 2.7 ng/g tissue) in six Fischer 344 rats compared with ANF content (3.03 +/- 0.2 ng/g tissue) in six Fischer 344 rats exposed only to room air. Ozone increased ANF content in the heart fivefold in the same animals from 288 +/- 39.6 ng/g tissue in the rats exposed to room air to 1,473 +/- 234.8 ng/g tissue in those exposed to ozone. Ozone also doubled the concentration of ANF in the circulatory system. This study demonstrates that ozone does increase ANF in the lungs, heart, and circulatory system, suggesting that ANF may mediate the decreased blood pressure and pulmonary edema observed with ozone exposure.