Daily short-term head-up tilt can prevent structural changes in arteries of tail-suspended rats

The aim of the present study was to investigate the effectiveness of daily 4-h head up tilt (HUT) in preventing the structural changes in arteries from rats induced by tail-suspension (TS). TS rat model was used to simulate the physiological effects of microgravity. Daily 4-h HUT was used to simulate the effect of intermittent artificial gravity (IAG). The results showed that TS alone induced an increase in the vessel media layer cross-sectional area (CSA), media wall thickness (T), mean number of smooth muscle cell layers (NCL) in basilar artery, and a decrease in these parameters in anterior tibial artery. Both the hypertrophic and atrophic changes in these arteries that might occur due to TS alone can be prevented by a 4h/d HUT treatment.