Design and Experimental Validation of Hindlimb Unloading Rat Suspension Device with Adjustable Body Position

The rat tail-suspension model was improved in this paper to develop a new type of adjustable body position hindlimb unloading suspension device for rats, which was used to investigate the effect of changes in body fluid distribution under simulated microgravity on bone metabolism in rats. 36 Sprague-Dawley rats were randomly divided into four groups: Control (CON) group, Head-Down-Tilt (HDT) group, Head-Horizontal (HH) group and Head-Up-Tilt (HUT) group. 21 days later, rats were detected for Bone Mineral Density (BMD) with DXA. Severe bone loss occurred in all three groups of rats under the simulated microgravity effect, and the hindlimb BMD of HH and HUT groups significantly increased compared with HDT group. The experimental results show that the changes in body fluid distribution may play an important role on the bone loss caused by simulated microgravity effect, and the new rat hindlimb unloading suspension device can adjust the body position (body fluid) of rats for simulated microgravity effect study.