EPA Science Inventory

Fate of pathologically bound oxygen resulting from inhalation of labeled ozone in rats

Citation:

Hatch, G., R. Slade, AND J. Mckee. Fate of pathologically bound oxygen resulting from inhalation of labeled ozone in rats. Environmental Health Insights. Libertas Academica Ltd, North Harbour, New Zealand, 7:43-58, (2013).

Description:

Inhaled ozone (03) reacts chemically with respiratory tissues where it forms adducts with most biomolecules. We quantified the plasma concentrations and urinary excretion of 18O in rats exposed to 1803 in order to gain insight into 0 injury and repair. Male Fischer 344 rats were exposed to l8O3 (2 ppm, 6 hr or 5 ppm, 2 hr) and urine was collected twice daily for 4 days. Increased 180 was detected in dried blood plasma at 7 hr post exposure and in dried urine for at least 4 days post exposure with higher excretion rates at night. Total 180 excreted was — 53% of the estimated amount of 18O3 retained by the rat during 18O3 exposure. Urinary 180 appeared to be of respiratory origin (not ingested), it was enriched in the >500 MW fraction, and it was stable to 250°C. Pre-exposure to unlabeled 03 a week earlier did not alter the excretion of 180 into urine following 18O3 exposure. We conclude that reaction products originating from 18O3 inhalation enter the circulation and are excreted into urine with only moderate recycling.

Purpose/Objective:

This is the first demonstration of ozone reaction products entering the circulation then the urine. Results have relevance to the mode of action of ozone, the identification of biomarkers for oxidative stress, and the interpretion of the adversity of formation of ozone adducts in the lung. The study exposed rats to oxygen-18 labeled ozone.

URLs/Downloads:

doi:10.4137/EHI.S12673   Exit

EPHD-13-069-ABSTRACT-FATAL.PDF   (PDF,NA pp, 354.155 KB,  about PDF)

Record Details:

Record Type: DOCUMENT (JOURNAL/PEER REVIEWED JOURNAL)
Start Date: 09/10/2013
Completion Date: 09/10/2013
Record Last Revised: 10/28/2013
Record Created: 09/10/2013
Record Released: 09/10/2013
OMB Category: Other
Record ID: 259940

Organization:

U.S. ENVIRONMENTAL PROTECTION AGENCY

OFFICE OF RESEARCH AND DEVELOPMENT

NATIONAL HEALTH AND ENVIRONMENTAL EFFECTS RESEARCH LAB

ENVIRONMENTAL PUBLIC HEALTH DIVISION

CARDIOPULMONARY AND IMMUNOTOXICOLOGY BRANCH