摘要
Objective To explore whether remote ischemic preconditioning(RIPC)can prolong the time of ultra-intense exercise(110%VO2max)by increasing the maximum cumulative oxygen deficit(MA-OD),and the specific ways of energy supply of the anaerobic metabolic system.Methods Twenty-four racquet athletes(22.2±2.0 years;174±9 cm;67.1±12.4 kg)completed three supramaximal intensi-ty tests on a treadmill at 110%VO2max intensity to exhaustion separated with Control,Placebo and RIPC interventions.RIPC was induced on the limbs on both sides(5×5 min alternating bilateral occlu-sion 220 and 60 mmHg for Placebo and RIPC interventions,respectively).Moreover,all groups under-went a fourth test with incremental load,and a fifth test with constant load at 40%,50%,60%,70%and 80%VO2max.Results The time to exhaustion and the MAOD of the RIPC group were both greater than those in the Placebo and Control groups(P<0.05).However,no significant differences were found in the average alternative maximal accumulated oxygen deficit(MAODALT),lactic anaerobic metabolism,alactic anaerobic metabolism and parameters of excess post-exercise oxygen consump-tion dynamic curve of the three groups(P>0.05).Meanwhile,in the RIPC group,the average MAOD was significantly higher than MAODALT(P<0.05).Pearson correlation analysis showed a significant rela-tionship between the improvement of MAOD and an increase in exhaustion time after RIPC interven-tion.Conclusion RIPC can improve supramaximal exercise performance of racquet athletes by enhanc-ing their MAOD,and the enhancement of glycolysis energy supply and lactic acid elimination is a po-tential intermediary of the improvement of sports performance.
摘要
Alpinia officinarum Hance of the Chinese traditional herb for the treatment of emesis,abdominal pain and diarrhea has been used to counteract gastric disease induced by indomethacin in rats without obvious side effects.However,the role of herb-drug interaction between indomethacin and A.officinarum based on pharmacokinetic,tissue distribution and excretion still remains unknown.In this study,an ultra-fast liquid-tandem mass spectrometry(UFLC-MS/MS)method was developed for simultaneous determina-tion of indomethacin and its three metabolites,O-desmethylindomethacin(ODI),deschlor-obenzoylindomethacin(NDI)and indomethacin acyl-β-D-glucuronide(IDAβG)by oral administration of indomethacin solution with and without the ethanolic extract of A.officinarum and applied to comparative pharmacokinetic,tissue distribution and excretion studies.Our results clarified that oral administration of A.officinarum produced significant alterations in the pharmacokinetic parameters of indomethacin.And the pharmacokinetic interaction between indomethacin and A.officinarum reduced the systemic exposure of indomethacin and increased its elimination.Tissue distribution results demonstrated that co-administration of A.Officinarum could not reduce the accumulation of indo-methacin in the target tissue of the stomach,but could accelerate the excretions of indomethacin and its three metabolites including ODI,NDI and IDAβG in the bile and feces of rats in the excretion study.Therefore,A.Officinarum might have a gastrointestinal protective effect through the interaction role with indomethacin based on the pharmacokinetics and excretion in rats.
摘要
Objective To observe the effect of a repeated-sprint training on the speed-endurance of basketball players in a hypoxia environment.Methods Sixteen basketball players were divided into a hypoxiagroup and a normoxia group which had 8 persons each group.The 2 groups separatelyhad a repeated-sprint training with anaerobic power bicycles in a simulatedhypoxic environment at the altitude of 3000 meters and a normoxia environment for 4 weeks(twice a week).Before and after the training,the two groups of subjects had a shuttle run testing and a Wingateanaerobic powertestingin a normoxia environment.Then their blood were collected and measured the blood lactate level at the point-intime of after the shuttle run,3 min later,5 min later,7 min later,and 9 min later.Recorded the result of the shuttle run,the relative average power of the Wingateanaerobic powertesting,and carried on a statistic analysis of the data.Results Comparing with the performance of the shuttle run before the training,the performance of the 2 groups was improved obviously after the four-week-long training (P<0.05).But there was no significant difference between the 2 groups(P>0.05).The rate of blood lacticacid clearance in the hypoxia group was higher than that in the normoxia group,and there was a significant difference at 7 min (P<0.01).The relative average power of the hypoxia group had a significant improvement(P<0.05),while the normoxia group had no significant change(P>0.05).There was no significant difference of the relative average power between the two groups.Conclusion Repeatedsprint training can improve basketball players' speed-endurance.Repeated-sprint training in a hypoxic environment can effectively improve basketball players' ability of reducing blood lactate in their body,and the improvement of this aerobic ability can help athletes to have a better performance in competitions.