The Effect of Spacecraft Simulated Condition on Serum Leptin in Rats

Physiological changes in spacecraft situation (endurance of gravity and circadian rhythm changes) can alter the neuromodulator. The objective of the current study was to determine the effects of 14 days of simulated microgravity and alteration of circadian rhythm (as simulated spacecraft situation) on the serum leptin level in rats. 32 male Wistar rats were divided into four groups (free motion groups with 12/12 hours or 45/45 minutes dark/light cycles and unloading tail suspension condition groups with 12/12 hours or 45/45 dark/light cycles). The serum leptin level was analyzed 14 days after the beginning of the intervention by ELISA. Data were analyzed by the two-way ANOVA. The data showed that the unloading situation significantly increased the serum leptin level. However, light/dark changing cycles had no significant effect on the serum leptin level. It seems that the unloading situations were much more effective than the light/dark changing cycles on the serum leptin level.