Ascorbic acid turnover in the mouse following acute ozone exposure

Area of Science:

• Biochemistry
• Toxicology
• Environmental Health

Background:

• Ozone (O3) is a major air pollutant with known adverse health effects.
• Ascorbic acid (vitamin C) is a critical antioxidant. Its role in ozone toxicity is not fully understood.

Purpose of the Study:

• To investigate the impact of ozone exposure on ascorbic acid levels and metabolism in Swiss Webster mice.
• To determine if ozone exposure affects ascorbic acid synthesis, degradation, or distribution.

Main Methods:

• Mice were exposed to 1.5 ppm ozone for 5 days.
• Radio-labeled [1-14C] ascorbic acid was administered post-exposure.
• Ascorbic acid levels and disappearance rates were measured in serum, lung, liver, and carcass over 9 days.

Main Results:

• Ozone exposure led to transient decreases in serum and liver ascorbic acid.
• Lung ascorbic acid levels increased post-ozone exposure.
• The biological half-life of ascorbic acid in the carcass was prolonged, indicating altered metabolism or distribution.

Conclusions:

• Ozone exposure significantly alters ascorbic acid dynamics in mice.
• Changes in tissue ascorbic acid levels reflect altered degradation, mobilization, or compartmentalization, not increased synthesis.
• These findings highlight the complex interaction between air pollution and vitamin C metabolism.