OXYGEN-TOXICITY IN NEWBORN - EFFECT OF CHRONIC CONTINUOUS 100 PERCENT OXYGEN EXPOSURE ON LUNGS OF NEWBORN MICE

Abstract

Continuous exposure of newborn mice of a single, highly inbred strain to 100% O2 at normal atmospheric pressure for up to 6 wk resulted in a progressive evolution of pulmonary changes which consisted of dense fibrous tissue deposition, chronic bronchitis and bronchiolitis and emphysema. Survival of the experimental animals decreased with the duration of exposure. There was 18% survival after the 6th wk. While the pulmonary changes were evolving, lung growth was markedly inhibited in the experimental animals, but lung weight increased significantly. In contrast to the adult mouse, survival of a substantial percentage of newborn mice for at least 6 wk was possible, but it was associated with severe changes in pulmonary structure that doubtlessly led to serious derangement of cardiopulmonary functions.