RESUMEN
Objective To study the effect of Exendin-4 on oxidative stress and neural apoptosis following spinal cord injury (SCI). Methods Adult male SD rats, with weight between 200-250 g, were randomly divided into three groups (12 in each group):Sham group, SCI group and Exendin-4 group (Ex-4 group). Rats in Sham group achieved spinal cord exposure. SCI group and Ex-4 group were induced according to Allen′s test (using a weight-drop device). Rats in Ex-4 group were ad?ministrated with Exendin-4 (10 μg/rat) through intraperitoneal injection immediately after establishment of SCI models. Rats in Sham group and SCI group were given the same volume of normal saline solution instead. Level of malondialdehyde (MDA) and the activity of catalase (CAT) were assessed in spinal cord tissues 24 hour after drug administrations. Neural apoptosis was detected by TUNEL staining and the expression levels of caspase-9 and AIF were determined using Western blot. Results Compared with Sham group, the levels of MDA, caspase-9 and AIF as well as neuronal apoptosis rate in?creased obviously, while activity of CAT decreased markedly in SCI group(P<0.01). Compared with SCI group, the levels of MDA, caspase-9 and AIF as well as the neuronal apoptosis rate decreased obviously, while activity of CAT increased re?markably in Exendin-4 group(P < 0.01). Conclusion Exendin-4 restrain neural apoptosis following spinal cord injury through relieving oxidative damage.
RESUMEN
Objective To detect the effects of the selective mitochondrial fission inhibitor-Mdivi-1 on the malondi-alolehyde (MDA), glutathione (GSH) as well as cytochrome C (Cyt-C) in neuronal mitochondria and neuronal apoptosis. Methods Thirty-six adult female SD rats (250-300 g) were randomly divided into 3 groups (n=12):sham operation (Sham) group, single spinal cord injury (SCI) group and Mdivi-1 pretreatment (1.20 mg/kg, Mdivi-1) group. In sham group, the rats’ spinal cord was exposed, but no hit. The rat model of spinal cord injury was established by Allen’s method in SCI group and Mdivi-1 group. In Mdivi-1 group, rats were given Mdivi-1 through the tail vein 15 min before spinal cord injury, and SCI group received the same amount of dimethyl sulfoxide (DMSO). Rats in Sham group were sacrificed 8 h after exposing spinal cord. Rats in SCI group and Mdivi-1 group were sacrificed at 8 h after the spinal cord injury, then were removed the spinal cord T9-11. The contents of MDA and GSH in mitochondria of spinal cord tissues were detected with spectrophotometer. The expressions of Cyt-C protein in the mitochondria and cytoplasm were detected by Western blot assay. The neuronal apoptosis was assessed by TUNEL staining. Results Compared with Sham group, levels of Cyt-C and GSH in mitochondria were decreased significantly (P<0.01), while levels of MDA in mitochondria, Cyt-C in cytoplasm and the neuronal apopto-sis were increased significantly in SCI group (P<0.01). Compared with SCI group, Cyt-C and GSH levels in mitochondria were increased significantly in Mdivi-1 group (P<0.01), however, MDA in mitochondria,Cyt-C in cytoplasm and the neuro-nal apoptosis were significantly reduced (P<0.01). Conclusion Mdivi-1 can relieve neurons from mitochondrial oxidative damage, inhibit the release of cytochrome C and neuronal apoptosis after acute spinal cord injury, which plays a role in pro-moting the recovery of spinal cord function.