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AIM:Taurine has been shown to be an effective scavengerof hypochlorous acid (HOCl).The role of HOCl is wellestablished in tissue damage associated with inflammationand injury.In the present study,the effect of HOCl on nuclearnucleoside triphosphatase of hepatocytes and the ability oftaurine to prevent this effect were investigated.METHODS:Isolated hepatic nuclei from rat liver wereexposed to HOCl with or without taurine.The NTPase activityon nuclear envelope was assayed using ATP and GTP assubstrates,respectively.RESULTS:The first series of experiments evaluated thetoxicity of HOCl and the efficacy of taurine to protect NTPase.HOCl at 10~(-9)-5×10~(-6)mol/L reduced nuclear NTPase activitiesin a concentration dependent manner (ATP and GTP assubstrates) (P<0.01).HOCl at 10~(-6)mol/L reduced the NTPaseactivity by 65% (ATP as substrate) and 76% (GTP assubstrate).Taurine (10~(-7) to 10~(-4)mol/L) was tested forprotection against HOCl at 10~(-6)mol/L and the nuclei treatedwith 5×10~(-4)mol/L taurine exhibited only 20% and 12%reduction in NTPase activities compared to untreatedcontrols.A second study was performed comparing taurineto glutathione (GSH).GSH and HOCl at 10~(-6)mol/L exhibited46% and 67.4% reduction in NTPase activities comparedwith control.GSH (10~(-4)mol/L) which was incubated withthe nuclei and HOCl still exhibited 44.2% and 44.8%reduction in NTPase activities of untreated control.Taurinewith HOCl only exhibited 15.2% and 17.1% reduction inNTPase activities,which provided more powerful protectionagainst HOCl than GSH.The third experiment was undertakento evaluate the specificity of taurine against HOCl.Incubationof rat hepatic nuclei with Fe~(3+)/H_2O_2 (1m mol/L vs5μ mol/L)resulted in a decrease in nuclear NTPase activities (P<0.01).When hepatic nuclei were incubated with Tau (10~(-4)mol/L)and Fe~(3+)/H_2O_2 (1m mol/L vs 5μ mol/L),nuclear NTPaseactivities were only slightly increased as compared with thatof incubation with Fe~(3+)/H_2O_2 alone.However,GSH failed toalter the NTPase activities induced by Fe~(3+)/H_2O_2.CONCLUSION:The present findings indicate that HOCl can act as an inhibitor of nuclear NTPase.Taurine canantagonistically reduce the toxicity of HOCI to NTPase.
AIM: Taurine has been shown to be an effective scavenger of hypochlorous acid (HOCl). The role of HOCl is wellestablished in tissue damage associated with inflammation and injury. In the present study, the effect of HOCl on nuclearnucleoside triphosphatase of hepatocytes and the ability of tauine to prevent this effect were investigated. METHODS: Isolated hepatic nuclei from rat liver wereexposed to HOCl with or without taurine. NTPase activity on nuclear envelope was assayed using ATP and GTP assubstrates, respectively .RESULTS: The first series of activities evaluated the toxicity of HOCl and the efficacy of taurine to protect NTPase.HOCl at 10 ~ (-9) -5 × 10 -6 mol / L reduced nuclear NTPase activities in a concentration dependent manner (ATP and GTP assubstrates) (P <0.01) .HOCl at 10 ~ (-6) mol / L reduced the NTPaseactivity by 65% (ATP as substrate) and 76% (GTP assubstrate) .Taurine (10 ~ (-7) to 10 ~ (-4) mol / L) was tested for protection against HOCl at 10 ~ (-6) mol / L and the nuclei treatedwith 5 × 10 ~ (-4) mol / L taurine drawings only 20% and 12% reduction in NTPase activities compared to untreated controls. A second study was verified comparing taurineto glutathione (GSH) .GSH and HOCl at 10 ~ (-6) mol / L exhibited46% and 67.4% reduction in NTPase activities compared with control. GSH (10 ~ (-4) mol / L) which was incubated with the nuclei and HOCl still exhibited 44.2% and 44.8% reduction in NTPase activities of untreated control.Taurine with HOCl only exhibited 15.2% and 17.1% reduction inNTPase activities, which provide more powerful protection for host HOCl than GSH. third in was trynto evaluate the specificity of taurine against HOCl. Cubation of rat hepatic nuclei with Fe ~ (3 +) / H_2O_2 (1m mol / L vs 5μ mol / L) resulted in a decreased in nuclear NTPase activities (P <0.01) .When hepatic nuclei were incubated with Tau (10 -4 mol / L) and Fe 3+ / H 2 O 2 (1 mol / L vs 5 mol / L) Nuclear NTPaseactivities were only slightly increased as compared with that of incubation with Fe ~ (3 +) / H_2O_2 alone.However, GSHfailed toalter the NTPase activities induced by Fe ~ (3 +) / H_2O_2.CONCLUSION: The present findings indicate that HOCl can act as an inhibitor of nuclear NTPase. canuristically reduce the toxicity of HOCI to NTPase.