Decreased Skin-Mediated Detoxification Contributes to Oxidative Stress and Insulin Resistance

Abstract EN

The skin, the body's largest organ, plays an important role in the biotransformation/detoxification and elimination of xenobiotics and endogenous toxic substances, but its role in oxidative stress and insulin resistance is unclear.

We investigated the relationship between skin detoxification and oxidative stress/insulin resistance by examining burn-induced changes in nicotinamide degradation.

Rats were divided into four groups: sham-operated, sham-nicotinamide, burn, and burn-nicotinamide.

Rats received an intraperitoneal glucose injection (2 g/kg) with (sham-nicotinamide and burn-nicotinamide groups) or without (sham-operated and burn groups) coadministration of nicotinamide (100 mg/kg).

The results showed that the mRNA of all detoxification-related enzymes tested was detected in sham-operated skin but not in burned skin.

The clearance of nicotinamide and N1-methylnicotinamide in burned rats was significantly decreased compared with that in sham-operated rats.

After glucose loading, burn group showed significantly higher plasma insulin levels with a lower muscle glycogen level than that of sham-operated and sham-nicotinamide groups, although there were no significant differences in blood glucose levels over time between groups.

More profound changes in plasma H2O2 and insulin levels were observed in burn-nicotinamide group.

It may be concluded that decreased skin detoxification may increase the risk for oxidative stress and insulin resistance.