The effect of aminoguanidine on compression spinal cord injury in rats

The current study was performed to investigate the effect of aminoguanidine (AG) on spinal cord injury (SCI) in rat. AG (75, 150 and 300 mg/kg, i.p. respectively ) was administered to rats immediately following SCI. It was found that AG (150 mg/kg) significantly reduced spinal cord water content and improved motor function, however, AG at the doses of 75 and 300 mg/kg had no effect. Compared to SCI group without treatment, AG at the dosage of 150 mg/kg induced a reduction in the permeability of blood–spinal cord barrier (BSCB) after injury 48 h (from 59.8 ± 5.5 µl/g to 39.8 ± 3.8 µl/g), a 38% decrease of Malondialdehyde (MDA) values and a 1-fold increase of the Glutathione (GSH) levels at 12 h after SCI. And the expression of inducible nitric oxide synthase (iNOS) protein reached a peak at 24 h after injury, which was significantly attenuated by treatment with AG (150 mg/kg). In addition, the expression of AQP4 protein was down-regulated by the treatment of AG (150 mg/kg) at 24 h after SCI, and the changes still lasted at 48 h after injury. Our results indicated that AG could induce spinal cord edema clearance and improve motor function, which could be correlated with antioxidative property, the down-regulation of iNOS and AQP4 protein expression after SCI.