Delayed onset of obesity and glucose tolerance in interleukin 18 deficient mice by single housed condition

Abstract

Interleukin 18 (IL18) is a kind of proinflammatory cytokine that belongs to the interleukin-1 family. IL18 is associated with obesity and type 2 diabetes. To discover whether body composition parameters in IL18 deficient mouse are altered in single-housed condition, body weight, glucose tolerance, lipid profiles, fat masses, and size of white adipocytes were examined. Mice were housed singly and were divided as follows: C57BL/6 J male (B6-M), IL18 deficient male (IL18-M), C57BL/6 J female (B6-F), IL18 deficient female (IL18-M). Body weight statistically significantly increased in IL18-M at 9 months (p < 0.05). Glucose tolerance occurred in IL18-M at 6 and 9 months. Total cholesterol and HDL cholesterol were statistically significantly increased in IL18-F compared with B6-F at 9 and 12 months, respectively (p < 0.05). Also, total cholesterol of IL18-M was statistically significantly increased compared with B6-F and IL18-F at 9 months (p < 0.05). The perirenal and inguinal fat masses were statistically significantly increased in IL18-M at 9 months (p < 0.05). In addition, the size of white adipocytes was increased in IL18-M at 9 months. In single-housed condition, onset of obesity and glucose tolerance were delayed by 3 months in IL18-M. Taken together, these results suggest that housing condition is a very important factor for weight gain and onset of glucose tolerance in IL18 deficient male mouse.