Collagen Composition of the Skin from Obese and Lean Zucker Rats

Summary

The skins of obese Zucker rats contained per g wet weight significantly more lipid and significantly less water than did the skins from age and sex matched lean Zucker rats. The obese skins also contained less collagen than the lean skins when compared on the basis of mg collagen per g wet weight, per g dry weight, or per cm² of skin; however, no difference was found when the skins were compared on the basis of mg collagen per g lipid-free dry weight. The solubility properties of the collagen from obese and lean skins were the same while the break strength of the obese skins was decreased. The results indicate that skins from obese Zucker rats have a normal collagen composition but an abnormal lipid composition. The reduced break strength of the skin from obese rats, due probably to the decreased amount of collagen per cm² of skin caused by a displacement of collagen fibers by lipid, may explain the frequent skin tearing observed in the obese rats.