Effect of tanshinone ⅡA on urodynamics in rats with neurogenic bladder after suprasacral cord injury

English Keywords:Spinal cord injury  Tanshinone ⅡA  Neurogenic bladder  Urodynamic  Rat

English Abstract:

  【Abstract】 Objectives: To observe the effect of tanshinone ⅡA(TⅡA) on the urodynamic of neurogenic bladder after suprasacral cord injury in rats, and to explore the possible mechanism. Methods: 40 female adult Sprague-Dawley rats were randomly divided into 4 groups: Sham group(laminectomy only, n=10), SCI group(T9 spinal cord contusive injury, n=10), TⅡA group[SCI with intravenous injection of TⅡA(20mg/kg) at 1 to 7 days post-injury at the same time, n=10], MP group[SCI with intravenous injection of methylprednisolone(30mg/kg) once at post-injury, n=10]. SCI was generated by using NYU injury device with a 10g weight dropped from a height of 25mm. Sham group and SCI group were treated with intravenous injection of 1ml normal saline at 1 to 7 days post-injury at the same time. Bladder pressure curve and associated parameters were measured by urodynamic examination at two weeks after injury. T9 segment of spinal cord was extracted and the injury area of dorsal hemorrhage was observed by light microscope after H&E staining. The L6-S1 dorsal root ganglions(DRGs) were isolated at the same time. And the levels of cell apoptosis in L6-S1 DRGs were examined by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL) assay. The integrated optical density(IOD) of apoptotic cells in DRGs in each group was measured by Image Pro-Plus(IPP) 6.0 and statistical analyses were performed after that. Results: (1)At 2 weeks after surgery, urodynamic evaluation showed that the basal pressure(BP), micturition pressure (MP’) and threshold pressure(TP) in SCI group increased significantly compared with those in Sham group(P<0.05); BP, MP’ and TP in TⅡA group and MP group increased obviously compared with those in SCI group(P<0.05); there was no dramatically change of BP, MP’ or TP between TⅡA group and MP group. Secondly, SCI group, TⅡA group and MP group showed significantly changes in comparison of sham group, such as increase in residual volume(RV) and increase in voided volume(VV) and voiding efficiency(VE) (P<0.05); VV and VE in TⅡA group and MP group were obviously increased compared with those in SCI group(P<0.05); TⅡA group displayed marked decrease in RV and increase in VE in comparison with MP group(P<0.05). In addition, SCI group, TⅡA group and MP group showed more nonvoiding contractions(NVCs) and a reduction of intercontraction interval(ICI) compared with sham group(P<0.05); TⅡA group and MP group showed a marked change compared with SCI group, such as reduction in NVCs and increase in ICI(P<0.05); and there were less NVCs in TⅡA group than MP group(P<0.05). (2)At 2 weeks after surgery, the rate of dorsal hemorrhage area/normal tissue area was as following: 0.048±0.001 in SCI group, 0.006±0.003 in tanshinone ⅡA group, and 0.012±0.001 in MP group, the ratio in TⅡA group and MP group was decreased significantly compared with that in SCI group(P<0.05); and there was no obvious change between TⅡA group and MP group. (3)At 2 weeks after surgery, the IOD of apoptosis in L6-S1 DRGs was 0.67±0.37, 2.92±0.35, 1.81±0.27, 2.16±0.18 in Sham group, SCI group, TⅡA group and MP group, respectively. The IOD of apoptosis in SCI group, TⅡA group and MP group decreased dramatically compared with that in Sham group(P<0.05); but IOD of apoptosis in MP group, TⅡA group increased significantly compared with that in SCI group(P<0.05); there was no obvious difference between TⅡA and MP group. Conclusions: TⅡA may improve urodynamic parameters of neurogenic bladder after suprasacral cord injury, so that it improves bladder function. TⅡA has a similar effect of MP and it may provide a new idea for the treatment of neurogenic bladder after spinal cord injury.