To investigate the influence of such individual factors as gender,age and tissues in vitro to the postmortem interval(PMI) by the Fourier transform infrared(FTIR) spectrometer in animal experiments.SD rats were classi...To investigate the influence of such individual factors as gender,age and tissues in vitro to the postmortem interval(PMI) by the Fourier transform infrared(FTIR) spectrometer in animal experiments.SD rats were classified into male and female groups,different age groups(21-day,42-day and 63-day group),and tissues in vitro and in vivo groups.The rats were sacrificed by cervical dislocation,whose bodies were kept in a controlled environmental chamber set at(20±2) ℃ and 50% humidity.The liver,kidney,spleen,myocardium,brain,lung and skeletal muscle tissues were collected for measurement from time zero to 48 h postmortem.With the change of PMI,no obvious changes were found in the main FTIR absorbance peaks and their ratios at different time points.All the experimental groups showed no significant changes when compared with the controls.The gender,age and tissues in vitro were not found to be contributing factors in the estimation of PMI via FTIR spectroscopy.展开更多
The aim of the current study was to investigate the spectra in the different organs of the rats which died of massive hemorrhage;to explore their spectral changes 15 days postmortem and the best mathematical model wit...The aim of the current study was to investigate the spectra in the different organs of the rats which died of massive hemorrhage;to explore their spectral changes 15 days postmortem and the best mathematical model with different band absorption ratio changes to postmortem interval(PMI);and to compare the spectral changes of different temperature.Thirty male Sprague-Dawley rats were sacrificed by cutting abdominal aorta,and the cadavers were divided equally and kept at 4 ℃,20 ℃ and 30 ℃ in the control chamber.From the same rat,seven different organs were sampled at intervals of 1-15 days postmortem,and then measured by Fourier transfom infrared(FTIR) spectrometer.Six mathematical model functions were explored.The absorbance of bands and band absorbance ratios of absorption peak in each organ showed a time-dependent increase or decrease,most band absorbance ratios remaining stable for 7-15 days postmortem.Cubic model functions of the various bands absorbance ratios against PMI showed a stronger related coefficient.The absorbance bands with obvious changes at 20 ℃ showed stabilized tendencies at 4 ℃ and significant changes at 30 ℃ within 15 days postmortem.In addition,FTIR spectroscopy revealed a time-dependent metabolic process,with potential of being used to estimate PMI during 7 days postmortem,which merits further investigation.展开更多
本研究分析宰后牛肉成熟14 d过程中细胞自噬的变化规律及其与牛肉品质间的关系。牛肉宰后成熟过程中,肉色方面,L^(*)值随成熟时间延长而升高,a^(*)值、b^(*)值均呈现先升高后降低的趋势;嫩度随成熟时间延长不断提高,剪切力与肌间线蛋白(...本研究分析宰后牛肉成熟14 d过程中细胞自噬的变化规律及其与牛肉品质间的关系。牛肉宰后成熟过程中,肉色方面,L^(*)值随成熟时间延长而升高,a^(*)值、b^(*)值均呈现先升高后降低的趋势;嫩度随成熟时间延长不断提高,剪切力与肌间线蛋白(Desmin)表达量均呈现下降趋势(P<0.05);保水性随成熟时间的延长而下降,贮藏损失率和蒸煮损失率上升(P<0.05)。进一步对自噬相关蛋白进行研究,牛肉宰后成熟过程中,Beclin-1与微管相关蛋白1轻链3作为细胞自噬发生的标志性蛋白,其表达量均呈先升高后降低的趋势,并在12 h达到最大。调控自噬的AMP活化蛋白激酶(AMP-activated protein kinase,AMPK)-哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)-酵母Atg1同源蛋白激酶(UNC-51 like kinase 1,ULK1)通路作为一条重要的能量代谢通路,在缺血缺氧环境下能够诱导细胞自噬的发生。本研究结果表明,牛肉宰后成熟过程中AMPK、p-AMPKThr172、ULK1的蛋白表达量均呈先升高后降低的趋势,并在12 h达到最大,mTOR表达量则持续下降(P<0.05),说明细胞自噬在宰后0~12 h增强。相关性分析结果显示,宰后自噬相关蛋白表达水平与牛肉的肉色呈负相关,与蒸煮损失、剪切力、Desmin蛋白相对表达量呈正相关(P<0.05)。综上所述,宰后牛肉成熟336h过程中可能通过AMPK-mTOR-ULK1通路激活细胞自噬进而对牛肉品质起到一定的调控作用。展开更多
基金Acknowledgement This research was supported by the National Natural Science Foundation of China （No. 81072509） and the Shanghai Key Laboratory of Forensic Medicine （No. KF0905）.
文摘To investigate the influence of such individual factors as gender,age and tissues in vitro to the postmortem interval(PMI) by the Fourier transform infrared(FTIR) spectrometer in animal experiments.SD rats were classified into male and female groups,different age groups(21-day,42-day and 63-day group),and tissues in vitro and in vivo groups.The rats were sacrificed by cervical dislocation,whose bodies were kept in a controlled environmental chamber set at(20±2) ℃ and 50% humidity.The liver,kidney,spleen,myocardium,brain,lung and skeletal muscle tissues were collected for measurement from time zero to 48 h postmortem.With the change of PMI,no obvious changes were found in the main FTIR absorbance peaks and their ratios at different time points.All the experimental groups showed no significant changes when compared with the controls.The gender,age and tissues in vitro were not found to be contributing factors in the estimation of PMI via FTIR spectroscopy.
基金funded by the Council of National Natural Science Foundation of China(No.81001350)
the Science and Technology Commission of Shanghai Municipality(No.09ZR1432900)
文摘The aim of the current study was to investigate the spectra in the different organs of the rats which died of massive hemorrhage;to explore their spectral changes 15 days postmortem and the best mathematical model with different band absorption ratio changes to postmortem interval(PMI);and to compare the spectral changes of different temperature.Thirty male Sprague-Dawley rats were sacrificed by cutting abdominal aorta,and the cadavers were divided equally and kept at 4 ℃,20 ℃ and 30 ℃ in the control chamber.From the same rat,seven different organs were sampled at intervals of 1-15 days postmortem,and then measured by Fourier transfom infrared(FTIR) spectrometer.Six mathematical model functions were explored.The absorbance of bands and band absorbance ratios of absorption peak in each organ showed a time-dependent increase or decrease,most band absorbance ratios remaining stable for 7-15 days postmortem.Cubic model functions of the various bands absorbance ratios against PMI showed a stronger related coefficient.The absorbance bands with obvious changes at 20 ℃ showed stabilized tendencies at 4 ℃ and significant changes at 30 ℃ within 15 days postmortem.In addition,FTIR spectroscopy revealed a time-dependent metabolic process,with potential of being used to estimate PMI during 7 days postmortem,which merits further investigation.
文摘本研究分析宰后牛肉成熟14 d过程中细胞自噬的变化规律及其与牛肉品质间的关系。牛肉宰后成熟过程中,肉色方面,L^(*)值随成熟时间延长而升高,a^(*)值、b^(*)值均呈现先升高后降低的趋势;嫩度随成熟时间延长不断提高,剪切力与肌间线蛋白(Desmin)表达量均呈现下降趋势(P<0.05);保水性随成熟时间的延长而下降,贮藏损失率和蒸煮损失率上升(P<0.05)。进一步对自噬相关蛋白进行研究,牛肉宰后成熟过程中,Beclin-1与微管相关蛋白1轻链3作为细胞自噬发生的标志性蛋白,其表达量均呈先升高后降低的趋势,并在12 h达到最大。调控自噬的AMP活化蛋白激酶(AMP-activated protein kinase,AMPK)-哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)-酵母Atg1同源蛋白激酶(UNC-51 like kinase 1,ULK1)通路作为一条重要的能量代谢通路,在缺血缺氧环境下能够诱导细胞自噬的发生。本研究结果表明,牛肉宰后成熟过程中AMPK、p-AMPKThr172、ULK1的蛋白表达量均呈先升高后降低的趋势,并在12 h达到最大,mTOR表达量则持续下降(P<0.05),说明细胞自噬在宰后0~12 h增强。相关性分析结果显示,宰后自噬相关蛋白表达水平与牛肉的肉色呈负相关,与蒸煮损失、剪切力、Desmin蛋白相对表达量呈正相关(P<0.05)。综上所述,宰后牛肉成熟336h过程中可能通过AMPK-mTOR-ULK1通路激活细胞自噬进而对牛肉品质起到一定的调控作用。
