Mechanistic effects of spinal cord section on regional blood flow and sympathetic vascular tone

摘要

The aims of this study were to investigate the effects of spinal cord section at Thoracic 1 on celiac or mesenteric flow and sympathetic vascular tone in order to understand the influence of spinal cord injury on regional vascular functions. The spinal cord was transected between the 1st and 2nd dorsal vertebrae under ether anesthesia. One hour after spinal transaction, arterial pressure (AP) and regional blood flow were measured in a conscious resting state. The percent decrease in peripheral resistance calculated as AP divided by regional blood flow was used as a measure of spinal sympathetic vasoconstrictor tone for resistance vessels of a particular region. Celiac tone in both NCR and SHR was supraspinal in origin and was enhanced in SHR, whereas mesenteric tone in both rats was spinal in origin and was suppressed reflexively in a neuraxis intact state. Spinal transection decreased regional flow rates. Spinal cord injury may impair regional vascular functions by decreasing cardiac output due to dilation of capacitance vessels and vasodilation in peripheral vascular beds.