Inhibitory Effect Of TSPN Preconditioning On Astrocytes Activation In Rats Of Inflammatory Visceral Pain

Objective:To investigate the influence of total saponins of panax notoginseng(TSPN)preconditioning on the behaviour and astrocytes in the spinal dorsal cord of rats withacute inflammatory visceral pain, and to reveal the mechanism of TSPNpreconditioning influence inflammatory visceral pain.Methods:54healthy adult SD rats were randomly divided into normal group(n=6), NSpreconditioning group(n=24), TSPN preconditioning group(n=24). The normal grouprats were fed routinely, proceed without drug preconditioning; the NS preconditioninggroup and TSPN preconditioning group rats were received an intraperitoneal injectionof1%acetic acid(10ml/kg) after intraperitoneal injection of normal saline(2.86ml/kg)or7mg/ml TSPN(2.86ml/kg) for7d. The writhing test was observed and the visceralpain index (VPI) scores were measured every15minutes immediately afterintraperitoneal injection of acetic acid; The rats were sacrificedat different intervals(30,60,90,180min) after the inflammatory visceral pain modelswere established, randomly. The number of neutrophils in the submucosa of jejunawas observed by hematoxylin-eosin(HE) staining; The expression of glial fibrillaryacidic protein(GFAP) in L4-S2spinal cord was compared by immunohistochemistry. Result:1.The behavior resultsThe behavior results showed that peak of VPI scores of the NS preconditioninggroup at15-30min(119.75±11.61), the peak of VPI scores of the TSPNpreconditioning group at30-45min(55.22±17.40); compared with the NSpreconditioning group, the VPI scores of the TSPN preconditioning groupsignificantly decreased at0-15,15-30,30-45,45-60,60-75min.2.HE staining resultsHE staining results showed that the submucosa of jejuna without infiltration ofneutrophils in the normal group; The number of neutrophils in the submucosa ofjejuna of the NS preconditioning30,60,90,180min survival group was1.50±0.22,4.50±0.22,4.33±0.21,4.33±0.61and the number of neutrophils in the submucosa ofjejuna of the TSPN preconditioning30,60,90,180min group was1.33±0.21,4.00±0.52,4.17±0.48,3.67±0.76. Compared with the NS preconditioning group, thenumber of neutrophils in the submucosa of jejuna of the TSPN preconditioning groupwas no significant difference.3.Immunohistochemistry resultsImmunohistochemistry results showed that the mean gray value of the normalgroup was17.67±0.84; the mean gray value of the NS preconditioning30,60,90,180min survival group was31.00±0.89,61.00±1.79,36.33±2.73,31.00±0.89;the mean gray value of the TSPN preconditioning30,60,90,180min survival groupwas18.00±2.37,32.33±1.03,26.67±1.03,28.00±2.37. the peak of GFAP value ofthe preconditioning groups at60min; compared with the normal group, theexpression of GFAP of the NS preconditioning groups and the TSPN preconditioning60,90,180min survived groups significantly increased; compared with the NSpreconditioning groups, the expression of GFAP of the TSPN preconditioning groupssignificantly reduced at30,60,90min survival time. Conclusion:1. TSPN preconditioning can relieve the inflammatory visceral pain of SD ratssignificantly.2. The mechanisms of TSPN preconditioning attenuate inflammatory visceralpain is related to inhibit the activation of astrocytes in the spinal dorsal horn.