Effects of different photoperiods on weight, blood glucose and cholesterol of mice (Mus musculus).

Abstract

Light is a zeitgeber known to modulate the circadian rhythm of both animals and plants. In this study, the researchers aim to test whether different photoperiods have any effect on the weight, blood glucose and cholesterol of mice. Forty-eight male mice were divided into three groups and exposed to a 12:12 Light-dark (LD) cycle, 4:20 LD cycle and 20:4 LD cycle. Blood was drawn from each mouse for subsequent assay and weight was measured from six mice per group every two weeks for nine weeks. Results show that the length of light exposure did not significantly alter the weight, blood glucose and cholesterol level of the mice. These findings may suggest that there are factors other than the length of light exposure that may disrupt the circadian rhythm of some physiological parameters.