Effect Of Paralysis Of The Abdominal Wall Muscles By Botulinum Toxin A To Iah

Objective:To observe the effect of botulinum toxin A–induced paralysis of abdominal muscleson intra-abdominal hypertension by establishing an accurate method of measurement ofintra-abdominal pressure and an effective animal model of intra-abdominal hypertension.Methods：1An accurate method of the measurement of intra-abdominal pressure of the rats wasconfirmed.Pressure of six different pressure levels(10,20,30,40,50,60cmH2O) in vitro wasmeasured by the modified method and the traditional one. For ten rats, theirintra-abdominal pressure of seven different pressure levels(10,15,20,25,30,35,40cmH2O) was measured by the modified method and the traditional one simultaneously.Agreements between the measurements from the two methods and standard values wereassessed following Pearson correlation, paired t-test.2A rat model of intra-abdominal hypertension was established.24female Wistar rats were randomly assigned to3groups(IAP10mmHg,IAP15mmHg, IAP20mmHg).We increased intra-abdominal pressure of the rats withperfusing saline, using the modified method to measure the intra-abdominal pressure of therats. we kept pressure of every group, observing the mortality of rats at the points ofintra-abdominal hypertension3h、6h、9h、12h.3The effect of botulinum toxin A–induced paralysis of abdominal muscles onintra-abdominal hypertension.40female Wistar rats were randomly assigned to experimental or paired controlgroup by weight. When the rat model of intra-abdominal hypertension was first established,the experimental rats and the paired control rats’ abdominal cavities were infusedrespectively with saline, about370ml/kg, ensuring that the intra-abdominal pressure of the two groups was about15mmHg.3days after the experimental group injected withbotulinum toxin A, their abdominal cavities were infused respectively with saline, about370ml/kg, but the intra-abdominal pressure of the group was not reaching to15mmHg, soabdominal cavities of them continued to be infused with saline, ensuring that theintra-abdominal pressure of the experimental group would reach to15mmHg,recordingwater volume of injection, about490ml/kg;the paired control rats’ abdominal cavities wereinfused respectively with saline, about370ml/kg,recording the intra-abdominal pressure.Abdominal cavities of them continued to be infused with saline, reaching to490ml/kg,recording the intra-abdominal pressure.Both of the groups were drawing blood at different time points(1h before operation，IAH3h and3h after IAH) for determining blood levels of superoxide dismutase(SOD) andmalondialdehyde(MDA).Results:1An accurate method of the measurement of intra-abdominal pressure of the rats wasconfirmed.1.1The traditional method and the modified one were tested in vitro.The values of the two methods and the standard ones were positive correlation forpressure of six different pressure levels(10,20,30,40,50,60cmH2O) in vitro. There wereno differences between the values of the measurements of the two methods and thestandard values(P>0.05).1.2The traditional method and the modified one were tested in the intra-abdominalpressure of the rats.The values of the two methods and the standard ones were positive correlation forpressure of seven different pressure levels(10、15、20、25、30、35、40cmH2O) in abdominalcavities of rats. There were significant differences between the values of the measurementsfrom the traditional method and the standard ones (P<0.05). There were no significantdifferences between the values of the measurements from the modified method and thestandard ones (P>0.05).2A rat model of intra-abdominal hypertension was established.The death rate of the rats of IAP10mmHg varied unconspicuously at the points ofIAH3h、6h、9h、12h,but the death rate of the rats of IAP15mmHg varied conspicuously atthese time points. The rats of IAP20mmHg were all dead within6h,7of them were deadwithin3h. 3The effect of botulinum toxin A–induced paralysis of abdominal muscles onintra-abdominal hypertension.When the rat model of intra-abdominal hypertension was first established, theexperimental rats and the paired control rats’ abdominal cavities were infused respectivelywith saline, about370ml/kg, ensuring that the intra-abdominal pressure of the two groupswas about15mmHg.3days after the experimental group injected with botulinum toxin A,their abdominal cavities were infused respectively with saline, about370ml/kg, but theintra-abdominal pressure of the group was about11.3mmHg, abdominal cavities of themcontinued to be infused with saline, ensuring that the intra-abdominal pressure of theexperimental group was about15mmHg,recording water volume of injection, about490ml/kg; the paired control rats’ abdominal cavities were infused respectively with saline,about370ml/kg, comparing the intra-abdominal pressure of the two groups with each other,there were significant differences(P<0.05). Abdominal cavities of them continued to beinfused with saline, reaching to490ml/kg, comparing the intra-abdominal pressure of thetwo groups with each other, there were significant differences (P<0.05).At IAH3h and3h after IAH removed, both SOD and MDA have significantdifferences when compaired with the normal level(P<0.05).T he two indexes of the pairedcontrol group have more varies than the experimental group(P<0.05).Conclusion:1The modified method of the measurement of intra-abdominal pressure is morestable and accurate than the traditional one.2The rats of IAP15mmHg are the better models of intra-abdominal hypertension foranimal studies.3The paralysis of the abdominal wall muscles by botulinum toxin A could improvethe volume of abdominal cavities and reduce the intra-abdominal hypertension.