Inhibitory effect of cold stress against acetaminophen-induced hepatic injury in B6C3F1 and ICR mice

The effect of cold stress (at 0 +/- 1 degrees C for 3 h) on acetaminophen-induced hepatic injury was investigated in B6C3F1 and ICR mice. When acetaminophen (250 mg/kg) was injected intraperitoneally in B6C3F1 mice, the plasma GPT activity was significantly increased by 93 or 107-fold at 6 h or 24 h after the drug injection. However, when B6C3F1 mice were exposed to cold stress, the increase in plasma GPT activity induced by acetaminophen was significantly inhibited by 53% and 44%, respectively. On the other hand, when acetaminophen at the same dose was injected in ICR mice, the activity of plasma GPT was increased by g-fold at 6 h, or 16-fold at 24 h after the drug injection. The increased plasma GPT activity elicited a significant inhibition of 35% and 36%, respectively, by the exposure to cold stress. These results suggest that acetaminophen-induced hepatic injury may be blocked by physical stress in mice.