The Effect of Naloxone on the Na+ K+ ATPase Activity Changes Following Experimental Spinal Cord Injury

ABSTRACT

The Na+ K+ ATPase activity, whose disturbance have been implicated in the pathophysiology of a variety of disease processes, have been shown to be reduced in traumatized spinal cord and in ischemic brain made by decapitation or carotid artery occlusion by many authors, but MacMillan contrary documented the increase of this ferment in ischemic rat brain following the electrocautery of the bilateral vertebral arteries and carotid arteries. This experiment was intended to study the cause of the above two contradictory results and the effect of Naloxone to the Na+ K+ ATPase activity following experimental spinal cord injury. Thirty cats were divided to 3 groups Control No. 1, control No.2 and Naloxone groups. The Na+ K+ ATPase activity was measured by variation of Kang & Lee method and the experimental spinal cord injury was made by falling 20 gm. of iron bar from 20 cm height to exposed thoracic cord. 1) In control No. 1 group the Na+ K+ ATPase activity increased 21.4% after 30 minutes of trauma showing significant difference(p<0.05). 2) In control No. 2 group it increased 13.8%(p<0.01) after 5 minutes, 11.6%(p<0.05) after 30 minutes showing significant difference. 3) In Naloxone group (10 mg/kg was injected I.V. before 30 minutes of trauma) it did not show any significant change after 5 and 30 minutes of trauma. 4) Discussion was made upon above experimental results with literature review.