ABSTRACT
[Objective]To research the influence of spinal cord blood flow(SCBF) and the evoked potential(EP) by the extramarrow impacting and to explore the correlation and regularity between the spinal cord blood flow and evoked potential after spinal cord injury.[Method]Normal 120 SD rats were randomized into 4 groups,with 30 in each.Group A was the control group.In groups B,C,D,impacts of 10,15,20N were given to lamina respectively.The blood flow of impacting position and evoked potential were observed at different time points including 0 min,1 h,6 h,1 d,6 d,12 d,24 d.[Result]The blood flow of spinal cord represents a dimning trend with the impacting load raising.The blood flow of group A,had no marked change,the SEP and MEP also.The blood flow of group B represented a temporaly lowing,then recovered normal,the SEP and MEP also.The blood flow of group C and D represented a continuous lowing,then slowly raising.The group C recovered normal at 24d,the group D still lower than normal.[Conclusion]The impact load to lamina can influence the spinal cord function through altering the spinal cord blood flow.There is evident correlation between the SCBF and EP.
ABSTRACT
Objective To study the influences of impact of different loads to lamina on spinal cord with a closed spinal cord injury model and to explore the mechanisms of blood vessels in spinal cord injury. Methods 120 normal male SD rats were randomized into 4 groups, with 30 in each. Group A served as the control group which received no impact. In Groups B, C and D,impacts of 10, 15 and 20 N were given to lamina respectively. The blood flow in the spinal cord central gray matter and the dorsal white matter, the blood pressure and the heart rate were observed at different experimental time points. Results No obvious change was observed in the blood pressure and heart rate in every group at different time points. The spinal cord blood flow (SCBF) in Groups C and D varied in a regular pattern. Conclusions The impact load to lamina can affect the spinal cord mainly by altering the spinal cord microcirculation. The influence is the most obvious on the blood flow of microcirculation of the gray matter.
ABSTRACT
A growing body of biochemical, physiological, and pharmacological evidence has suggested that oxygen free radical-induced lipid peroxidation plays a key role in progressive posttraumatic spinal cord ischemia. Recently, it has been reported that the newly developed compound, U74006 F, a non-glucocorticoid 21-aminosteroid, is extremely potent as an inhibitor of lipid peroxidation and effective preventor from the posttraumatic ischemia. In this investigation, the effects of 21-aminosteroid U74389F, analog of U74006F on posttraumatic spinal cord blood flow and somatosensory evoked potential have been studied in cats. The results of this study are summarized as follows:(1) U74389F, given 3 mg/kg, blood flow decreased significantly and somatosensory response returned to none of five cats. (2) U74389F, given 10 mg/kg or 20 mg/kg, the blood flow did not decreased and maintained near the preinjury level. The recovery rate of somatosensory evoked potential ranged from 40 to 60%. (3) There was no statistical difference of blood flow change between the cats treated with 10 mg/kg and those treated with 20 mg/kg of U74389F. It is thought that the adequate dosage of U74389F to prevent posttraumatic spinal cord ischemia is more than 10 mg/kg or 20 mg/kg of U74389F, was statistically significant compared to much more decrease in naloxone-treated cats. The reason is thought to be much longer half life of U74389F in serum. From the above results, it is speculated that U74389Fhas beneficial effect on posttraumatic spinal cord ischemia and functional recovery. The effects last longer than those of naloxone.
Subject(s)
Animals , Cats , Evoked Potentials, Somatosensory , Half-Life , Ischemia , Lipid Peroxidation , Naloxone , Oxygen , Spinal Cord Ischemia , Spinal CordABSTRACT
The effect of naloxone on blood flow was studied in cats subjected to 400 gm-cm contusion injuries of the thoracic spinal cord. Ten cats were treated with 10 mg/kg naloxone 45 to 60 minutes after injury. Ten cats were given 10 mL of saline instead of naloxone, and 10 cats were neither injured nor treated. Hydrogen clearance was used to measure blood flow in the lateral white column at the contusion site. Naloxone, given intravenously, significantly improved the blood flow rates in the lateral column white matter. At 2 hours after injury, the mean blood flow in the saline-treated cats fell to 6.01+/-0.90 mL/100 gm/min, whereas it increased 8.47+/-1.14 mL/100gm/min in naloxone-treated cats (p<0.05). The authors conclude that naloxone may be useful for spinal cord injury.