BACKGROUND： Central sensitization, a state of increased excitability of nociceptive neurons in the spinal dorsal horn following peripheral tissue injury and/or inflammation, is an important mechanism underlying hyper...BACKGROUND： Central sensitization, a state of increased excitability of nociceptive neurons in the spinal dorsal horn following peripheral tissue injury and/or inflammation, is an important mechanism underlying hyperalgesia and neuropathic pain. Participation of the glutamate-glutamine cycle in central sensitization of the spinal cord remains poorly understood. OBJECTIVE： To determine whether the astrocyte-neuronal glutamate-glutamine cycle is involved in formalin-induced central sensitization in the spinal cord. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Institute of Orthopedics, Second Hospital, Lanzhou University, China from September 2007 to August 2008. MATERIALS： Methionine sulfoximine （MSO, 0.1 mmol/L）, glutamine （0.25 mmol/L）, and formalin were used for this study. METHODS： A total of 43 male, Sprague Dawley rats, aged 4 months, were randomly assigned to a sham operation group （n = 6） and a model group （n = 37）. Rats in the model group received intrathecal infusion in the spinal cord. 7 days later, 37 model rats were randomly divided into PBS, MSO, glutamine, MSO ＋ glutamine and formalin subcutaneous injection alone groups. The PBS, MSO, glutamine, MSO ＋ glutamine groups were respectively intrathecally injected with PBS, MSO, glutamine, MSO ＋ glutamine （50 μL each）, and then infused with 10 μL of saline. Rats from the sham operation group were not subjected to intrathecal infusion in the spinal cord. At 15 minutes after intrathecal injection, a rat model of formalin-induced inflammatory pain was established by subcutaneous injection of 5% formalin （50 μL） in the left hindpaw. MAIN OUTCOME MEASURES： Changes in spontaneous nociceptive behavior （licking/biting or flinching） were observed following formalin injection into the rat hindpaw. RESULTS： Compared with the PBS group, duration of licking/biting was significantly shortened, and flinching frequency was significantly diminished in the MSO group （P 〈 0.05）. Compared with the MSO group, duration of licking/biting was significantly prolonged, and flinching frequency was significantly increased in the MSO ＋ glutamine group （P 〈 0.05）. There was no significant difference in inflammatory pain behaviors among the sham operation, PBS, glutamine, MSO ＋ glutamine, and formalin subcutaneous injection alone groups （P 〉 0.05）. CONCLUSION： The astrocyte-neuronal glutamate-glutamine cycle in the spinal cord was shown to be involved in central sensitization induced by formalin subcutaneous injection into the hindpaw.展开更多
Our previous behavioral studies have indicated that the astroglial glutamate-giutamine cycle is involved in the process of formalin-induced spinal cord central sensitization, but there was little morphological evidenc...Our previous behavioral studies have indicated that the astroglial glutamate-giutamine cycle is involved in the process of formalin-induced spinal cord central sensitization, but there was little morphological evidence. In this study, double-labeling immunofluorescence techniques showed that after rats were intrathecally injected with PBS and plantarly injected with formalin, glial fibrillary acidic protein （GFAP） and glutamine synthesase （GS） expression were increased and GFAP/GS coexpression was changed to include layers III and IV. After intrathecal injection of methionine sulfoximine, a GS specific inhibitor, the formalin-induced change in expression and coexpression of GFAP and GS in spinal cord dorsal horns was inhibited. The morphology, distribution and quantity of astrocytes recovered to normal levels. An intrathecal glutamine injection reversed the inhibitory effect of methionine sulfoximine. Astrocytes showed significant activation and distribution extended to layers V and VI. The present study provides morphological evidence that the astroglial glutamateglutamine cycle is involved in the process of formalin-induced spinal cord central sensitization.展开更多
Several potentially practical biochemical processes in plant systems still remain hidden, especially the NADH-glutamate dehydrogenase (GDH) synthesis of nongenetic code-based RNA that optimizes crop nutritious yield b...Several potentially practical biochemical processes in plant systems still remain hidden, especially the NADH-glutamate dehydrogenase (GDH) synthesis of nongenetic code-based RNA that optimizes crop nutritious yield by degrading superfluous genetic code-based RNA. In continued characterization of the biochemistry of cowpea grain yield, GDH was purified by electrophoresis from seeds of cowpea treated with solutions of stoichiometric mixes of mineral salts. The GDH was made to synthesize RNAs in the amination (α-KG/NADH/</span><span><span></span><span style="font-family:""><span style="font-family:Verdana;">) and then in the deamination (L-Glu/NAD</span><sup><span style="font-family:Verdana;">+</span></sup><span style="font-family:Verdana;">) direction. The initial product RNAs were captured and sequenced. The grand challenge was to discover the specific molecular roles of the redox enzyme in the optimization of cowpea grain yields. In the amination direction, the GDH hexamers synthesized plus-RNA, but in the deamination direction</span></span><span style="font-family:Verdana;">,</span><span style="font-family:""><span style="font-family:Verdana;"> they synthesized minus-RNA. The plus-RNAs and minus-RNAs were homologous to about the same numbers of different mRNAs encoding the key enzymes that regulate photosynthesis;saccharide biochemistry and glycolysis;phenylpropanoid biosynthesis;nodulation nitrogen fixing processes;dehydrin drought and glutathione environmental stress resistance processes;purine, pyrimidine, DNA, RNA and essential amino acid biosynthesis;storage protein vicilin accumulation;isoflavone earliness of cowpea maturity;peroxidase synthesis of lignin and sequestration of CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> to enrich soil organic carbon contents;triglyceride physiology in the biosynthesis of bioactive compounds that render cowpea resistant to insects and fungi;etc</span></span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;">, all of which constitute the GDH chemical pathways for discrimination of biochemical, physiological, metabolic, genetic reactions;and optimization of cowpea dry grain yields. Each stoichiometric mix of mineral salts produced optimally yielding biochemical variant of purple hull cowpea;the K</span><span style="font-family:""> </span><span style="font-family:Verdana;">+</span><span style="font-family:""> </span><span style="font-family:Verdana;">K</span><span style="font-family:""> </span><span style="font-family:Verdana;">+</span><span style="font-family:""> </span><span style="font-family:Verdana;">K mix was spectacular because it increased the grain yield to 7598 kg from the 3644 kg</span><span style="font-family:""><span style="font-family:Verdana;">·</span><span style="font-family:Verdana;">ha</span><sup><span style="font-family:Verdana;">-1</span></sup> </span><span style="font-family:Verdana;">in the control cowpea. Optimized nutritious staple crop yield buttresses food security. The synthesis of plus-RNA in amination and minus-RNA in deamination is an economic tactical plan in biochemistry for the selection of superfluous mRNAs that would be degraded to assure the survival of cowpea growing under unfavorable environmental conditions.展开更多
基金the National Science Foundation of China,No.30800333
文摘BACKGROUND： Central sensitization, a state of increased excitability of nociceptive neurons in the spinal dorsal horn following peripheral tissue injury and/or inflammation, is an important mechanism underlying hyperalgesia and neuropathic pain. Participation of the glutamate-glutamine cycle in central sensitization of the spinal cord remains poorly understood. OBJECTIVE： To determine whether the astrocyte-neuronal glutamate-glutamine cycle is involved in formalin-induced central sensitization in the spinal cord. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Institute of Orthopedics, Second Hospital, Lanzhou University, China from September 2007 to August 2008. MATERIALS： Methionine sulfoximine （MSO, 0.1 mmol/L）, glutamine （0.25 mmol/L）, and formalin were used for this study. METHODS： A total of 43 male, Sprague Dawley rats, aged 4 months, were randomly assigned to a sham operation group （n = 6） and a model group （n = 37）. Rats in the model group received intrathecal infusion in the spinal cord. 7 days later, 37 model rats were randomly divided into PBS, MSO, glutamine, MSO ＋ glutamine and formalin subcutaneous injection alone groups. The PBS, MSO, glutamine, MSO ＋ glutamine groups were respectively intrathecally injected with PBS, MSO, glutamine, MSO ＋ glutamine （50 μL each）, and then infused with 10 μL of saline. Rats from the sham operation group were not subjected to intrathecal infusion in the spinal cord. At 15 minutes after intrathecal injection, a rat model of formalin-induced inflammatory pain was established by subcutaneous injection of 5% formalin （50 μL） in the left hindpaw. MAIN OUTCOME MEASURES： Changes in spontaneous nociceptive behavior （licking/biting or flinching） were observed following formalin injection into the rat hindpaw. RESULTS： Compared with the PBS group, duration of licking/biting was significantly shortened, and flinching frequency was significantly diminished in the MSO group （P 〈 0.05）. Compared with the MSO group, duration of licking/biting was significantly prolonged, and flinching frequency was significantly increased in the MSO ＋ glutamine group （P 〈 0.05）. There was no significant difference in inflammatory pain behaviors among the sham operation, PBS, glutamine, MSO ＋ glutamine, and formalin subcutaneous injection alone groups （P 〉 0.05）. CONCLUSION： The astrocyte-neuronal glutamate-glutamine cycle in the spinal cord was shown to be involved in central sensitization induced by formalin subcutaneous injection into the hindpaw.
基金the National Natural Science Foundation of China, No. 30800333the Fundamental Research Funds for the Central Universities, No. lzujbky-2010-148
文摘Our previous behavioral studies have indicated that the astroglial glutamate-giutamine cycle is involved in the process of formalin-induced spinal cord central sensitization, but there was little morphological evidence. In this study, double-labeling immunofluorescence techniques showed that after rats were intrathecally injected with PBS and plantarly injected with formalin, glial fibrillary acidic protein （GFAP） and glutamine synthesase （GS） expression were increased and GFAP/GS coexpression was changed to include layers III and IV. After intrathecal injection of methionine sulfoximine, a GS specific inhibitor, the formalin-induced change in expression and coexpression of GFAP and GS in spinal cord dorsal horns was inhibited. The morphology, distribution and quantity of astrocytes recovered to normal levels. An intrathecal glutamine injection reversed the inhibitory effect of methionine sulfoximine. Astrocytes showed significant activation and distribution extended to layers V and VI. The present study provides morphological evidence that the astroglial glutamateglutamine cycle is involved in the process of formalin-induced spinal cord central sensitization.
文摘Several potentially practical biochemical processes in plant systems still remain hidden, especially the NADH-glutamate dehydrogenase (GDH) synthesis of nongenetic code-based RNA that optimizes crop nutritious yield by degrading superfluous genetic code-based RNA. In continued characterization of the biochemistry of cowpea grain yield, GDH was purified by electrophoresis from seeds of cowpea treated with solutions of stoichiometric mixes of mineral salts. The GDH was made to synthesize RNAs in the amination (α-KG/NADH/</span><span><span></span><span style="font-family:""><span style="font-family:Verdana;">) and then in the deamination (L-Glu/NAD</span><sup><span style="font-family:Verdana;">+</span></sup><span style="font-family:Verdana;">) direction. The initial product RNAs were captured and sequenced. The grand challenge was to discover the specific molecular roles of the redox enzyme in the optimization of cowpea grain yields. In the amination direction, the GDH hexamers synthesized plus-RNA, but in the deamination direction</span></span><span style="font-family:Verdana;">,</span><span style="font-family:""><span style="font-family:Verdana;"> they synthesized minus-RNA. The plus-RNAs and minus-RNAs were homologous to about the same numbers of different mRNAs encoding the key enzymes that regulate photosynthesis;saccharide biochemistry and glycolysis;phenylpropanoid biosynthesis;nodulation nitrogen fixing processes;dehydrin drought and glutathione environmental stress resistance processes;purine, pyrimidine, DNA, RNA and essential amino acid biosynthesis;storage protein vicilin accumulation;isoflavone earliness of cowpea maturity;peroxidase synthesis of lignin and sequestration of CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> to enrich soil organic carbon contents;triglyceride physiology in the biosynthesis of bioactive compounds that render cowpea resistant to insects and fungi;etc</span></span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;">, all of which constitute the GDH chemical pathways for discrimination of biochemical, physiological, metabolic, genetic reactions;and optimization of cowpea dry grain yields. Each stoichiometric mix of mineral salts produced optimally yielding biochemical variant of purple hull cowpea;the K</span><span style="font-family:""> </span><span style="font-family:Verdana;">+</span><span style="font-family:""> </span><span style="font-family:Verdana;">K</span><span style="font-family:""> </span><span style="font-family:Verdana;">+</span><span style="font-family:""> </span><span style="font-family:Verdana;">K mix was spectacular because it increased the grain yield to 7598 kg from the 3644 kg</span><span style="font-family:""><span style="font-family:Verdana;">·</span><span style="font-family:Verdana;">ha</span><sup><span style="font-family:Verdana;">-1</span></sup> </span><span style="font-family:Verdana;">in the control cowpea. Optimized nutritious staple crop yield buttresses food security. The synthesis of plus-RNA in amination and minus-RNA in deamination is an economic tactical plan in biochemistry for the selection of superfluous mRNAs that would be degraded to assure the survival of cowpea growing under unfavorable environmental conditions.
