Ambient Light On The Mouse Body Weight And Liver Lipid Changes

Affects of environmental light on body weight and levels of hepatic lipids were investigated. Constant darkness (DD) induces murine procolipase gene (mClps) to express in almost all organs in the mice. We found constant darkness had affected mice's body weight gain, liver index, serum triglyceride and other physiological indicators. The six-week-old C57BL/6 female mice had a significant decrease in body weight gain, liver index and serum triglyceride in DD for two weeks compared with the mice in LD condition. ( 2.1±0.88g vs. 3.6±0.85g, 4.55±0.30% vs. 5.74±0.65%, 1.11±0.21mmol/L vs. 1.47±0.24 mmol/L, respectively).High-fat feeding mice held in DD for 2 weeks exhibited a lower degree of hepatic steatosis than mice kept in LD.The mice maintained on DD also exhibited a decrease in the level of all-trans-retinol for 2 days, which suggests that the expression of mClps may cause the decomposition of retinyl esters.Variation of light waves had effects on the change of physiological indicators. The mice kept in the light between 505 to 525nm, 640 to 680nm decreased body weight gain and liver index, but the mice kept in the light between 505nm to 470nm, 610 to 530 nm had no effects compared to the mice housed in normal light-dark cycles.