BACKGROUND:Prostaglandin E1(PGE1)has been shown to play a regulatory role in vasodilatation,inflammation,and leukocyte migration and adhesion,but its effects on spinal cord microcirculation after traumatic spinal cord injury(SCI)remain poorly understood. OBJECTIVE:To investigate the mechanism underlying the protective effects of PGE1 administered during the acute phase of traumatic SCI in rats on the regulation of vascular-related factors and microcirculatory function. METHODS:Seventy-two female Sprague-Dawley rats were divided into three groups(n=24 per group):control group,SCI group,and PGE1 group.An in vivo SCI model was established using Allen's blow method.Rats in the PGE1 group were injected with PGE1(10 μg/kg)via the tail vein immediately after SCI.Spinal cord microcirculatory blood flow and oxygen saturation,spinal cord microvessel diameter and area,spinal cord water content,vascular function regulators(von Willebrand factor,thromboxane A2,prostacyclin,endothelin-1),and inflammatory factors(tumor necrosis factor-α,interleukin-1β)were measured at 2 and 24 hours after SCI. RESULTS AND CONCLUSION:At 2 hours after SCI,the diameter and area of spinal cord microvessels,spinal cord microcirculatory blood flow,and oxygen saturation in the PGE1 group were higher than those in the SCI group(P<0.05),the water content of the spinal cord was lower than that in the SCI group(P<0.05),and the level of plasma von Willebrand Factor,the ratio of thromboxane A2/prostacyclin of the spinal cord and the level of endothelin-1 were lower than those in the SCI group(P<0.05).At 24 hours after SCI,the spinal cord microvessel area,blood flow,and oxygen saturation of rats in the PGE1 group were higher than those in the SCI group(P<0.05),the spinal cord water content was lower than that in the SCI group(P<0.05),and the levels of plasma von Willebrand factor,spinal cord tissue thromboxane A2/prostacyclin ratio and the levels of endothelin-1,tumor necrosis factor-α and interleukin-1β were lower than those in the SCI group(P<0.05).The diameter and area of spinal cord microvessels,spinal cord microcirculatory blood flow and blood oxygen saturation of rats in the SCI group were higher than those in the SCI group at 24 hours post-injury(P<0.05),and the levels of plasma von Willebrand factor,spinal tissue thromboxane A2/prostacyclin ratio,tumor necrosis factor-α and interleukin-1β were higher than those at 2 hours post-injury(P<0.05),but the level of endothelin-1 in spinal cord tissue was lower than that at 2 hours(P<0.05).The blood flow and oxygen saturation of spinal cord microcirculation in the PGE1 group rats at 24 hours post-injury were lower than those at 2 hours post-injury(P<0.05),and the diameter and area of spinal cord microvessels and water content of the spinal cord were higher than those at 2 hours post-injury(P<0.05).The above results indicate that intravenous administration of PGE1 in SCI rats immediately after injury can regulate vascular function regulators,inflammatory factors and improve microcirculation of the spinal cord after SCI,which provides a potential basis for the search of drugs for the treatment of acute SCI.