Animal Model of Simulated Microgravity: A comparative study of hindlimb unloading via tail vs. pelvic suspension

Abstract

The aim of this study is to compare the effects of simulated microgravity in tail suspended (TS) as well as in pelvic suspended (PS) rats mimicking aspects of prolonged bed rest and sub‐clinical insulinopenia.Materials and MethodsAdult male Sprague‐Dawley rats divided into suspended and control‐non‐suspended groups (6 each per group), were subjected to two separate methods of suspension and maintained with regular food and water for two weeks. Body weights, food and water consumption, soleus muscle weights, malodialdehyde levels of soleus muscle and brain tissues were measured. Pressure‐pain threshold (PPT) was measured using Randall‐Selitto technique at regular 2–3 days intervals during one week before and 2 weeks after HLS.ResultsBody weights in suspended rats from day 10 are significantly different between groups. Food and water intakes are not different between control and suspended groups. Suspended rats had smaller soleus muscle weights and increased MDA levels (p <0.05). PPT were decreased below control after 5 days of PS and 10 days of TS and continued to drop till day 14. X‐ray images show less spinal deformity in PS rats as compared to TS rats.ConclusionsThese data suggest that both procedures develop peripheral neuropathy. Pelvic suspension appears to provide a suitable alternative to tail suspension for chronic hindlimb unloading alleviating excess stress.