Construction and Evaluation of a Rat Model of Postpartum Fatigue.

OBJECTIVES: The aim of the study was to construct and evaluate a rat model of postpartum fatigue. DESIGN: This is an article about animal model building. METHODS: Sprague-Dawley rats on the 1st day after delivery were randomized into control group and fatigue group. The deep sleep of rats was interfered with by forcing them to stand in water, to make the rats experience mental and physical fatigue. To maintain galactosis and lactation, rats and pups were caged for 90 min after every 3 h of separation. The control group was separated routinely without any stimulus. The model was evaluated from mental and physical fatigue on the 8th day and 15th day. The mental fatigue was evaluated by a water maze test and the rat's 5-hydroxytryptamine (5-HT) level in hippocampus, while the physical fatigue was evaluated using lactic acid level in serum and duration of weight-loaded forced swimming. RESULTS: Among the 7-day and 14-day modeling groups, compared with the control group, the success rate of water maze landing was significantly decreased, the time for water maze landing was significantly prolonged and 5-HT level in hippocampus significantly decreased in the fatigue group. With respect to physical fatigue, among the 7-day and 14-day modeling groups, the lactic acid level in serum in the fatigue group was significantly increased, and the duration of exhaustive swimming of rats was significantly shortened. LIMITATIONS: A small sample size was the main limitation of this study. CONCLUSIONS: We have successfully constructed a rat model of postpartum fatigue by forcing postpartum rats to stand in water, which was similar to a level of stress that contributes to the development of postpartum fatigue. Our model opens the door for future studies evaluating the effectiveness of pharmacological and behavioral therapies.