[Effects of Danshen injection on glial cell line-derived neurotrophic factor mRNA of acute spinal cord injury rats and its mechanisms].
OBJECTIVE
To observe effects of Danshen Injection (DSI) on glial cell line-derived neurotrophic factor (GDNF) in the gray matter of acute spinal cord injury (SCI) rats and to discuss its mechanisms.


METHODS
Totally 144 male SD rats were used to prepare the SCI model, and then they were randomly divided into three groups, i.e., the treatment group, the control group, and the SCI group, 48 in each group. Rats in the treatment group were intraperitoneally injected with DSI (at the daily dose of 1.78 mL/ kg), those in the control group were intraperitoneally injected with methylprednisolone (at the dose of 30 mg/kg in 23 h, the 23-h total dose calculated according to 5.4 mg/kg per hour 45 min later; injected in 4 times), but rats in the SCI group were not intervened. Besides, another 48 male SD rats were recruited as the sham-operation group (no injury of their spinal cords). The spinal motor functions were assessed on the first day, the third day, the 7th day, and the 14th day after SCI. Their expressions of GDNF mRNA were detected at the aforesaid time points.


RESULTS
The successful rate of modeling was 80.54% in this experiment. Within 14 days after SCI, bleeding, edema, and neuronal necrosis were obviously less in the treatment group than in the SCI group, but with no significant difference when compared with those of the control group. Compared with the sham-operation group at the same time points, the critical angle in the tilt board test was smaller in the SCI group on the first day, the third day, the 7th day, and the 14th day after SCI. The density of GDNF mRNA immunoreactivity was higher in the SCI group than in the sham-operation group at the same time points (P < 0.01). On the 1st day after SCI, the critical angle in the tilt board test was smaller in the treatment group after treatment than before treatment (P < 0.01). The critical angle and the density of GDNF mRNA immunoreactivity were lower in the treatment group than in the control group at the same time points (P < 0.05), but they were higher in the treatment group than in the SCI group at the same time points (P < 0.01). The density of GDNF mRNA immunoreactivity was higher in the treatment group on the 3rd day after SCI than on the 1st day after SCI, and than in the SCI group on the 3rd day after SCI (P < 0.01, P < 0.05). It was lower in the treatment group than in the control group on the 3rd day after SCI (P < 0.05). The critical angle in the tilt board test was higher in the treatment group on the 7th day after SCI than on the 3rd day after SCI, and than the SCL group on the 7th day after SCI (P < 0.01), but lower than the control group (P < 0.05). The density of GDNF mRNA immunoreactivity was higher in the treatment group than in the SCI group on the 7th day after SCI (P < 0.01). The critical angle in the tilt board test was higher in the treatment group on the 14th day after SCI than on the 7th day after SCL (P < 0.01, P < 0.05). The critical angle and the density of GDNF mRNA immunoreactivity were higher in the treatment group than in the SCI group on the 14th day (P < 0.01).


CONCLUSIONS
Salvia miltiorrhiza could attenuate edema and bleeding in the gray matter of SCL rats, and improve the microcirculation of the spinal cord, thus elevating the GDNF mRNA expression in the gray matter of acute SCI rats. It was an ideal drug for treating early SCI.
Orthopedic Institute of Fujian University of Traditional Chinese Medicine, Fuzhou 350108, China. weilimen@126.com
Li
L
Wei
Li
L
Zhang
D000818:Animals; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000378:metabolism*; D008297:Male; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D027561:Salvia miltiorrhiza; D013116:Spinal Cord / Q000187:drug effects* / Q000378:metabolism*; D013119:Spinal Cord Injuries / Q000378:metabolism*
D004365:Drugs, Chinese Herbal; D051100:Glial Cell Line-Derived Neurotrophic Factor; D012333:RNA, Messenger; C028972:dan-shen root extract