Decreased skin-mediated detoxification contributes to oxidative stress and insulin resistance.
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 N(1)-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 H(2)O(2) 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.
Department of Physiology, Medical College, Dalian University, Dalian 116622, China.
Xing-Xing
XX
Liu
Chang-Bin
CB
Sun
Ting-Tong
TT
Yang
Da
D
Li
Chun-Yan
CY
Li
Yan-Jie
YJ
Tian
Ming
M
Guo
Yu
Y
Cao
Shi-Sheng
SS
Zhou
D000818:Animals; D000975:Antioxidants / Q000737:chemistry; D001786:Blood Glucose / Q000378:metabolism; D002056:Burns / Q000378:metabolism*; D006003:Glycogen / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance; D008297:Male; D009536:Niacinamide / Q000031:analogs & derivatives / Q000494:pharmacology; D018384:Oxidative Stress; D051381:Rats; D017207:Rats, Sprague-Dawley; D012867:Skin / Q000378:metabolism*; D015262:Xenobiotics / Q000737:chemistry
D000975:Antioxidants; D001786:Blood Glucose; D007328:Insulin; D015262:Xenobiotics; D009536:Niacinamide; D006003:Glycogen; D006861:Hydrogen Peroxide; C024058:N(1)-methylnicotinamide