Experimental study on expression of endothelin-1 mRNA in spinal cord tissues from acute spinal cord injury

Objective To explore mRNA expression and action mechanism of endothelin 1(ET 1) in spinal cord injury (SCI). Methods The thoracic spinal cord (T 8 9 ) of rats was compressed by a load of 35 g for 5 minutes,which caused an acute and moderate injury.By means of in situ hybridization histochemistry (ISHH), the distributive particularities in time and location of the early expression of ET 1 messenger ribonucleic acid (ET 1 mRNA) in injured spinal cord tissues from rats were qualitatively and quantitatively measured. Results The expression of ET 1 mRNA increased 30 minutes after spinal cord compression and reached its climax at 4 hours. Then, it decreased slowly to normal level at 72 hours.The positive cells of the ET 1 mRNA expression were localized to neuronal cell bodies in spinal cord. The highly expressive regions were in the ventral horn (laminae IX). Conclusions An increase of ET 1 concentration in injured spinal cord tissues is mainly from its abnormal expression of transcription level. ET 1 is a key injury factor in secondary injury after acute spinal cord injury.