Comparative study of GDNF and methyl prednisolone on intracellular free calcium and containing water capacity after spinal cord injury in rats / 医学研究生学报

ABSTRACT

Objectives:To compare the effect of glial cell line-derived neurotrophic factor(GDNF) and methylprednisolone(MP) on intracellular free calcium(［Ca2+］i) and capacity of containing water(CCW) after spinal cord injury(SCI).　Methods:Forty-two SD rats were divided into four groups： control, GDNF,MP and GDNF+MP.GDNF and MP were supplied through subarachnoid cavity, tail vein and both of the above after T12 segments spinal cord injury by modified Allen crush method. Animals were executed and specimens were collected at 24 h, 72 h and 168 h after SCI.［Ca2+］i and CCW were measured using Fura-2 method.　Results:Both ［Ca2+］i and CCW of injured spinal cord in GDNF,MP, and GDNF+MP groups were lower than that of the control group at 24 h and 72 h after SCI(P<0.01).Levels of ［Ca2+］i and CCW in GDNF group was much higher than that of MP and MP+GDNF groups(P<0.01),but there was no difference between MP group and MP+GDNF group(P>0.05) 24 hours after SCI. Seventy-two hours after SCI,［Ca2+］i in GDNF group was higher than that in MP group, MP group was higher than MP+GDNF group(P<0.05).CCW of GDNF group exceeded that of MP and MP+GDNF group(P<0.01).［Ca2+］i in GDNF group was higher than that in MP group, and MP group was higher than MP+GDNF group(P<0.01) 7 days postoperatively, but for CCW, there were no differences among GDNF,MP and MP+GDNF groups(P>0.05).　Conclusions: Both GDNF,MP and GDNF + MP groups might reduce ［Ca2+］i and CCW of injured spinal cord. The curative effect of MP for SCI preponderate over that of GDNF, the effect of MP could be enhanced by adding GDNF.