Effects of subcutaneous transfection of human beta-nerve growth factor gene on expression of substance P in dorsal root ganglion in a rat model of diabetic neuropathic pain / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effects of subcutaneous transfection of human beta-nerve growth factor (Ad-hNGFβ) gene on the expression of substance P (SP) in the dorsal root ganglion in a rat model of diabetic neuropathic pain (DNP).Methods Male SD rats weighing 180-220 g were used in this study.Ten rats were randomly collected as normal control without DNP (group C).DNP model was made by intraperitoneal injection of streptozocin (STZ) 75 mg/kg.Seventy-five rats with DNP were randomly divided into 3 groups ( n =25 each):DNP group; Ad-hNGF group and Ad-LacZ group.Groups Ad-NGF and Ad-LacZ received subcutaneous transfection of 1.12 × 1010 PFU Ad-hNGFβ 10 μl and 1.12 × 1010 PFU Ad-LacZ 10 μl respectively after pain threshold was measured on 21d after STZ injection.The mechanical and thermal pain threshold was measured before STZ injection (baseline) and at 21,35 and 49 d after STZ injection.The expression of SP in the dorsal root ganglion was determined after the measurement of pain threshold on 49 d after STZ injection.Results Compared with group C,the mechanical and thermal pain threshold was significantly decreased at each time point after STZ injection in groups DNP,Ad-NGF and Ad-LacZ,and the expression of SP in the dorsal root ganglion was signilicantly downregulated in groups DNP and Ad-LacZ (P ＜ 0.05).Compared with group DNP,the thermal pain threshold was significantly increased on 49 d afar STZ injection,and the expression of SP in the dorsal root ganglion was significantly up-regulated in group Ad-NGF ( P ＜ 0.01 ),and no significant change was found in the mechanical and thermal pain threshold and the expression of SP in the dorsal root ganglion at each time point in group Ad-LacZ ( P ＞ 0.05).Conclusion Subcutaneous transfection of Ad-hNGFβ can attenuate DNP to some extent through upregulation of the expression of SP in rat dorsal root ganglion.