Mechanical and chemical properties of the skin and its collagen from lean and obese-hyperglycaemic (ob/ob) mice.

We have compared the mechanical and chemical properties of the skin and its collagen from 24-week-old obese-hyperglycaemic (ob/ob) and lean mice. The skin from obese mice was mechanically weaker and generated a lower hydrothermal isometric force. However, there were no significant differences from lean mice in the type of reducible cross-links in the collagen or in its solubility, although it contained more reducible cross-links and glycosylated lysine. The total amount of skin collagen was similar in obese and lean mice from 3 to 24 weeks of age but the skin surface area was 60% greater in 24-week-old obese mice. When corrected for collagen content the tensile strength of skin from obese mice was greater than that from lean mice and we suppose that the weakness of obese mouse skin is caused by a failure of collagen deposition to match the increase in skin surface area as the animals become obese.