Abstract:[Objective] To investigate the effects of salidroside on the spinal cord tissue expressions of aquaporin 1 (AQP-1) and aquaporin 4 (AQP-4) after acute spinal cord injury in rats. [Methods] Thirty-six rats were randomly divided into the sham operation group, the model group and the salidroside group, with 12 rats in each group. In the sham operation group, only laminectomy was performed, and normal saline was injected intraperitoneally after the operation. In the model group and the salidroside group, spinal cord injury models were established, and normal saline and salidroside were injected intraperitoneally after the operation, respectively. Samples were harvested 3 days after the operation to detect the moisture content of spinal cord tissues. In addition, Nissl, immunohistochemistry and TUNEL staining, as well as western blot and RT-PCR assay were carried out for detection. [Results] Compared with the sham operation group, the moisture contents of spinal cord tissues in the model group and the salidroside group were significantly increased, while compared with the model group, the moisture content of spinal cord tissues in the salidroside group was significantly decreased [(85.3±5.6)% vs (72.2±7.6)%, P< 0.001]. In term of Nissl staining, the morphology of nerve cells in the sham operation group was normal, while that in the model group was disordered, and that in the salidroside group was significantly improved compared with the model group. In term of immunohistochemistry, compared with the sham operation group, the positive expressions of NeuN in the model group and the salidroside group were significantly decreased, whereas compared with the model group, the positive expression of NeuN in the salidroside group was significantly increased [(0.4±0.4) vs (0.9±0.4), P<0.001]. In term of Tunel staining, compared with the sham operation group, the positive Tunel staining in the model group and the salidroside group was significantly increased, while compared with the model group, the positive staining in the salidroside group was significantly decreased [(0.8±0.1) vs (0.6±0.0), P<0.001]. In term of western blot assay, compared with the sham operation group, the relative protein expression levels of AQP-1 and AQP-4 in the model group and the salidroside group were significantly increased (P<0.05), while compared with the model group, the AQP-1 and AQP-4 expression in the salidroside group were significantly decreased (P< 0.05). As results of RT-PCR, compared with the sham operation group, the relative mRNA expression of AQP-1 and AQP-4 in the model group and the salidroside group were significantly increased (P<0.05), whereas compared with the model group, the AQP-1 and AQP-4 expression in the salidroside group were significantly decreased (P<0.05). [Conclusion] The salidroside down- regulates the expressions of AQP-1 and AQP-4 during the process of acute spinal cord injury, reduce edema and inhibit cell apoptosis.