Abstract: ObjectiveTo establish an experimental model of orthostatic hypotension (OH) after spinal cord injury (SCI) in rabbits and investigate the effect and relevant mechanism of tilting table exercise on OH.MethodsRabbit model of OH was established by completely transecting animal's spinal cord at the T₅ segment and putting animal on a 60° tilting table. Tilting table exercise was applied to training group for 28 days starting from 4th day after operation. Systolic blood pressure (SBP) and pulse rate (PR) were observed by non invasive sphygmobolometer of rabbit at 3rd, 10th, 17th, 24th and 31st day after the operation. The concentrations of plasma renin activity (PRA) and angiotensinⅡ (AngⅡ) of different position were detected with radio immunoassay at 31st day after operation.ResultsSBP at 60° head up tilt increased and difference of SBP between two positions decreased significantly in training group at 31st day. The concentrations of PRA and AngⅡ of SCI group and training group were higher than that of sham group. There were no significant differences in the concentrations of PRA and AngⅡ between training group and SCI group.Conclusion T₅ complete SCI can induce OH in rabbits. Tilting table exercise can partially improve OH after SCI in rabbit, which may be not related to activation of the circulating renin angiotensin system.

Key words: tilting table exercise, orthostatic hypotension (OH), spinal cord injury (SCI), renin angiotensin system