Mouse strain differences in ozone dosimetry and body temperature changes
Slade, R.; Watkinson, W.P.; Hatch, G.E.
American Journal of Physiology 272(1 Pt 1): L73-L77
1997
ISSN/ISBN: 0002-9513 PMID: 9038905 Document Number: 483674
Strain differences in susceptibility to inhaled ozone (O-3) have been observed in mice, with C57BL/6J (B6) mice reported to be more sensitive than C3H/HEJ (C3) mice when exposed to equal concentrations of O-3. To determine whether differences in the delivered dose of O-3 to the lung could help explain these differences, C3 and B6 mice were exposed to 18O-labeled ozone (18O-3), and the resulting 18O concentrations in pulmonary tissues were monitored as an indicator of O-3 delivered dose. Body core temperatures (T-co) of similarly treated mice were measured during O-3 exposures (using surgically implanted temperature probes) in an effort to correlate lung O-3 dose to changes in basal metabolism. Immediately after exposure to 18O-3, C3 mice had 46% less 180 (per mg dry wt) in lungs and 61% less in tracheas than B6 mice. Nasal 18O tended to be lower in the C3 mice, but these differences were not significant. Although both strains responded to the O-3 exposure with significant decreases in T-co, C3 mice had a 70% greater mean temperature times time product decrease during the exposure than B6 mice. These results suggest that the strain differences in O-3 susceptibility may be due to differences in O-3 dose to the lung, which may be related to differences in the ability of the mice to lower their T-co in response to O-3 exposure.