In this paper,the effect of sodium laurate(SL)on the properties of sodium lauroyl glutamate(SLG),such as surface activity,foam,wetting,emulsification,and resistance to hard water,has been systematically investigated.T...In this paper,the effect of sodium laurate(SL)on the properties of sodium lauroyl glutamate(SLG),such as surface activity,foam,wetting,emulsification,and resistance to hard water,has been systematically investigated.The results showed that the critical micelle concentration(cmc)of SLG was 0.30 mmol/L,and the surface tension at the cmc(γcmc)was 34.95 mN/m.With the increase of SL content,the efficiency of SLG solution in reducing the surface tension was decreased.When the SL content was increased,there was no significant change in the foaming ability and foam stability of SLG solutions.The increase of SL content improved both the emulsification and wettability of SLG,but reduced its water resistance.展开更多
Glial glutamate transporter-1(GLT-1)is the predominant subtype of glutamate transporters and is responsible for the clearance of extracellular glutamate and for limiting the concentration of extracellular glutamate.Ou...Glial glutamate transporter-1(GLT-1)is the predominant subtype of glutamate transporters and is responsible for the clearance of extracellular glutamate and for limiting the concentration of extracellular glutamate.Our previous studies have shown that the up-regulation of GLT-1 expression plays an important role展开更多
The experiment of glutamate synthase activity (GOGATA) in both leaf blades and roots under different nitrogen levels was carried out at Northeast Agricultural University in 1993. The result showed that GOGATA rose rap...The experiment of glutamate synthase activity (GOGATA) in both leaf blades and roots under different nitrogen levels was carried out at Northeast Agricultural University in 1993. The result showed that GOGATA rose rapidly to reach its peak from seedling stage to foliage rapid growth stage, and then declined gradually. GOGATA was enhanced with increasing nitrogen levels and had significant positive correlation with nitrogen levels at the middle stage of growth GOGATA in leaf blades was the strongest compared with crowns, petioles and roots, thus, it could represent the highest enzyme activity of the whole plant. GOGATA had quadratic curvilinear correlation with root yield and sugar production. GOGATA in leaf blades had significant positive correlation with α-NH 2-N at the foliage rapid growth stage while GOGATA in roots existed this relation at the latter stage of growth. GOGATA in roots had significant negative correlation with sugar content at harvest.展开更多
The experiment of Glutamate Dehydrogenase (GDH) activity in various plant parts under different nitrogen levels in frame culture during the whole period of growth was carried out on campus of Northeast Agricltural Uni...The experiment of Glutamate Dehydrogenase (GDH) activity in various plant parts under different nitrogen levels in frame culture during the whole period of growth was carried out on campus of Northeast Agricltural University in 1993. The result showed that GDH activity in leaf blades under four nitrogen applied levels rose rapidly to the acme from the seedling to foliage rapid growth stage, then diminished rapidly to the lower level at the latter stage of foliage rapid growth. This level was kept to harvest. GDH activity in roots at each growth stage under all nitrogen levels exhibited little disparity and did not show ostensible regularity of changes. GDH activity in leaf blades was stimulated with nitrogen, however, it reduced with nitrogen fertilizer applying further. GDH activity in leaf blades was the biggest compared with crowns, petioles and roots, which suggested that it could represent the highest enzyme activityof the whole plant.展开更多
OBJECTIVE Major depressive disorder(MDD) is a common mental illness,which shows serious dysfunction in emotion,motivation and cognition. The imbalance of monoamine neurotransmitter is the classic pathogenesis of depre...OBJECTIVE Major depressive disorder(MDD) is a common mental illness,which shows serious dysfunction in emotion,motivation and cognition. The imbalance of monoamine neurotransmitter is the classic pathogenesis of depression,but more and more evidence indicates that glutamatergic transmission may be the key factor leading to the occurrence of depression. However,the role of the membrane expression and regulation of glutamate receptors in the development of depression has not been elucidated. To address this issue,we have done series of experiments. METHODS Different methods and techniques,such as behavior,morphology,molecular biology and electrophysiology,were applied to investigate the impact of glutamate receptors and their subunits in the regulation of synaptic plasticity and the mechanism in depressive animal models. RESULTS Chronic social defeat stress(CSDS) can induce depressive behaviors in wildtype(WT) mice but not caspase-1 knockout(KO) mice. Further experiments showed that,in WT mice,CSDS induced a significant decrease in the membrane expression levels of the GluR1 and GluR2 subunits of AMPA receptors,the amplitudes of m EPSC in hippocampal CA1,meanwhile the long-term potentiation(LTP) at hippocampus SC-CA1 pathway was also impaired. Oppositely,this CSDS-induced reduction of the membrane expression of AMPA receptors was prevented by the knockout of caspase-1 or caspase-1 inhibitor,in which the expression of GluA1 and GluA2 were upregulated from(60.2±3.4)% and(63.9±3.7)% to(120.1±5.9)%and(112.6±9.6)%,respectively,while the total protein level of AMPA receptor subunits were not affected.On the other hand,a chronic intracerebroventricular injection of IL-1β,a downstream signal molecule of caspase-1,could induce depression-and anxiety-like behaviors in caspase-1 KO mice. CONCLUSION The caspase-1 can mediate the stress-induced depression-like behaviors by down-regulation of the membrane expression of AMPA receptors in hippocampus,the inhibition or knock-out of caspase-1can increase the expression of AMPA receptors in the membrane,thus reversing the depression-like behavior. Caspase-1 may serve as new target for depression therapy.展开更多
Neurotransmitters of the central nervous system were the important way to study the mechanism of anesthesia. The effect of different doses of xylazine anesthetic on the glutamate(Glu) and γ-aminobutyric-acid(GABA) we...Neurotransmitters of the central nervous system were the important way to study the mechanism of anesthesia. The effect of different doses of xylazine anesthetic on the glutamate(Glu) and γ-aminobutyric-acid(GABA) were investigated and the mechanism of xylazine anesthetic on the central nervous system were explored in this study. A total of 88 rats were randomly divided into three groups, including normal saline control group, group with low dose of xylazine and group with high dose of xylazine.Cerebrum, cerebellum, hippocampus, thalamus and brainstem were collected. The results showed that the concentration of Glu in the hippocampus, thalamus and brainstem decreased first and then increased, but it increased first and then decreased in the cerebrum and cerebellum during the period of anesthesia. The concentration of GABA in the cerebrum, thalamus, brainstem and hippocampus increased first and then decreased. The results showed that xylazine inhibited Glu and promoted GABA with different dose dependence. The results and methods could provide guides for the clinical use of xylazine.展开更多
OBJECTIVE Respiratory depression hinders the use of anaesthetics and sedative hypnotics.For emergency use,specific antagonists are currently administered to counteract respiratory depression.However,antagonists are of...OBJECTIVE Respiratory depression hinders the use of anaesthetics and sedative hypnotics.For emergency use,specific antagonists are currently administered to counteract respiratory depression.However,antagonists are often short-lasting and can have multiple unexpected side effects.A novel AMPA receptor modulator LCX001,synthesized by our Institute of Medicinal Chemistry,is expected to relieve suppressed respiration.To explore the mechanism and impact of LCX001 on protection against respiratory depression.METHODS LCX001 was tested to alleviate respiratory depression triggered by opioid,propofol and pentobarbital in the plethysmography recording.The acetic acid writhing and hot-plate tests were conducted to evaluate potential analgesic effect of LCX001.Binding assay and whole-cell recording were used to analyze the property of LCX001 on positive modulation.The function of AMPA receptors were determined by location of receptors inthe membrane and state of channel opening,and both processes were impressed by AMPA receptor regulatory proteins.According to the theory,the effect of LCX001 on the expression of stargazin was measured firstly by Western blotting.The variation of receptor surface location were observed by live cell imaging.The regulation on neuronal Ca2+and cell function was investigated intensively by Ca2+imaging to clarify mechanism of LCX001.RESULTS LCX001 effectively rescued and prevented opioid(fentanyl and TH-030418),propofol,and pentobarbitalinduced respiratory depression by strengthening respiratory frequency and minute ventilation by 30%-50% in rats.The acetic acid writhing test and hot-plate test revealed potent anti-nociceptive efficacy of LCX001 on increasing the inhibition rate and %MPE to 80% and 65% respectively,in contrast to some ampakines that did not affect analgesia.Furthermore,LCX001 potentiated[3 H]AMPA and L-glutamate binding affinity to AMPA receptors,and facilitated glutamateevoked inward currents in HEK293 cells stably expressing GluA2(R).At 10 mmol·L^(-1) glutamate evoked amplitudes,LCX001 at 100 μmol·L^(-1) increased the potency of glutamate induced currents by(1120 ± 60) pA,compared with that of(752 ± 35) pA in the control group.LCX001 also prominently promoted steady state/peak amplitude ratio.LCX001 significantly slowed down the desensitization rates of the AMPA ion channel,and inhibited current decay.Importantly,application of LCX001 generated a significant increase in GluA2(R) surface expression in a mechanism of stargazin up-regulation,and restrained opioidinduced abnormal intracel ular Ca2+load,which might participate in breathing modulation.CONCLUSION The typical positive modulatory impact and potential new mechanism of LCX001 might promote ampakines to be a therapeutic option for protection against respiratory depression.展开更多
OBJECTIVE AMPA-subtype iono⁃tropic glutamate receptors(iGluRs)mediate fast excitatory synaptic transmission in the mammali⁃an central nervous system(CNS).It plays the key role in many central nerves disorder such as e...OBJECTIVE AMPA-subtype iono⁃tropic glutamate receptors(iGluRs)mediate fast excitatory synaptic transmission in the mammali⁃an central nervous system(CNS).It plays the key role in many central nerves disorder such as epilepsy,depression and schizophrenia.Star⁃gazin(STZ,also named TARP-γ2),as the first TARPs found in CNS,potentiates AMPAR activity by attenuating deactivation and desensitization,enhancing recovery from desensitization,and facilitating agonist affinity and efficacy.However,it is still not fully understanding howγ-2 modu⁃late AMPAR gating.METHODS AND RESULTS The desensitization for different mutation of AMPAR andγ-2 was compared.It was shown that the electric attraction was involved in the interaction of AMPAR andγ-2.In addition,the interaction of KGK motif in ligand binding domain and pre-M1 chain of AMPAR and EX1 ofγ-2 modulate AMPAR opening and desensitization.Substitution of these charged residues had sur⁃prisingly effects on AMPAR desensitization kinet⁃ics.CONCLUSION The electric attraction has two impacts on the channels gating process the first destablizing the receptor closed state and enabling the channel opening,the second pro⁃moting the channels entering desensitization state upon the channel opening.展开更多
This article describes the characteristics of natural dusts, artificial dusts and industrial dusts, such as mineral phases, chemical components, morphological observation and size. Quartz and calcite are the main phas...This article describes the characteristics of natural dusts, artificial dusts and industrial dusts, such as mineral phases, chemical components, morphological observation and size. Quartz and calcite are the main phases of natural dusts and industrial dusts with high SiO2, CaO and low K2O, Na2O on the chemical composition. Natural dusts are mainly irregular shaped and some particle aggregation made of small dusts on the surface of large dust. Industrial dusts are globular and blob-like, but artificial dusts are columnar and fibrous. The fine particles are mainly in the range of 0.3-5 μm,of which the dusts of less than 5 μm are over 99%.The dissolution and electrochemical action of dusts in glutamic acid liquor at the simulated human body temperature (37 ℃) in 32 hours were investigated. The changes of pH values and electric conductivity of those dusts were similar, increased slowly in first 8 hours, and then the pH values increased rapidly. The total amount of dissolved ions of K, Ca, Na, Mg was 35.4-429 mg/L, particularly Ca was maximal of 20-334 mg/L. The total amount of dissolved ions of Fe, Zn, Mn, Pb, Ba was 0.18-5.59 ppm and the Al, Si was 3.0-21.7 mg/L. Each element dissolved rapidly relatively in first 16 hours. The relative solubility order of dusts in glutamic acid are: wollastonite > serpentine > sepiolite, the cement plant industrial dusts > power plant industrial dusts, and natural dusts have similar solubility. The wollastonite and power plant industrial dusts have highest solubility, which have high content of CaO; this shows there are a poorer corrosion-resisting ability and lower bio-resistibility. Sepiolite and cement plant industrial dusts have lowest solubility, which have high content of SiO2; this shows there are a higher corrosion-resisting ability and stronger bio-resistibility.展开更多
文摘In this paper,the effect of sodium laurate(SL)on the properties of sodium lauroyl glutamate(SLG),such as surface activity,foam,wetting,emulsification,and resistance to hard water,has been systematically investigated.The results showed that the critical micelle concentration(cmc)of SLG was 0.30 mmol/L,and the surface tension at the cmc(γcmc)was 34.95 mN/m.With the increase of SL content,the efficiency of SLG solution in reducing the surface tension was decreased.When the SL content was increased,there was no significant change in the foaming ability and foam stability of SLG solutions.The increase of SL content improved both the emulsification and wettability of SLG,but reduced its water resistance.
文摘Glial glutamate transporter-1(GLT-1)is the predominant subtype of glutamate transporters and is responsible for the clearance of extracellular glutamate and for limiting the concentration of extracellular glutamate.Our previous studies have shown that the up-regulation of GLT-1 expression plays an important role
文摘The experiment of glutamate synthase activity (GOGATA) in both leaf blades and roots under different nitrogen levels was carried out at Northeast Agricultural University in 1993. The result showed that GOGATA rose rapidly to reach its peak from seedling stage to foliage rapid growth stage, and then declined gradually. GOGATA was enhanced with increasing nitrogen levels and had significant positive correlation with nitrogen levels at the middle stage of growth GOGATA in leaf blades was the strongest compared with crowns, petioles and roots, thus, it could represent the highest enzyme activity of the whole plant. GOGATA had quadratic curvilinear correlation with root yield and sugar production. GOGATA in leaf blades had significant positive correlation with α-NH 2-N at the foliage rapid growth stage while GOGATA in roots existed this relation at the latter stage of growth. GOGATA in roots had significant negative correlation with sugar content at harvest.
文摘The experiment of Glutamate Dehydrogenase (GDH) activity in various plant parts under different nitrogen levels in frame culture during the whole period of growth was carried out on campus of Northeast Agricltural University in 1993. The result showed that GDH activity in leaf blades under four nitrogen applied levels rose rapidly to the acme from the seedling to foliage rapid growth stage, then diminished rapidly to the lower level at the latter stage of foliage rapid growth. This level was kept to harvest. GDH activity in roots at each growth stage under all nitrogen levels exhibited little disparity and did not show ostensible regularity of changes. GDH activity in leaf blades was stimulated with nitrogen, however, it reduced with nitrogen fertilizer applying further. GDH activity in leaf blades was the biggest compared with crowns, petioles and roots, which suggested that it could represent the highest enzyme activityof the whole plant.
文摘OBJECTIVE Major depressive disorder(MDD) is a common mental illness,which shows serious dysfunction in emotion,motivation and cognition. The imbalance of monoamine neurotransmitter is the classic pathogenesis of depression,but more and more evidence indicates that glutamatergic transmission may be the key factor leading to the occurrence of depression. However,the role of the membrane expression and regulation of glutamate receptors in the development of depression has not been elucidated. To address this issue,we have done series of experiments. METHODS Different methods and techniques,such as behavior,morphology,molecular biology and electrophysiology,were applied to investigate the impact of glutamate receptors and their subunits in the regulation of synaptic plasticity and the mechanism in depressive animal models. RESULTS Chronic social defeat stress(CSDS) can induce depressive behaviors in wildtype(WT) mice but not caspase-1 knockout(KO) mice. Further experiments showed that,in WT mice,CSDS induced a significant decrease in the membrane expression levels of the GluR1 and GluR2 subunits of AMPA receptors,the amplitudes of m EPSC in hippocampal CA1,meanwhile the long-term potentiation(LTP) at hippocampus SC-CA1 pathway was also impaired. Oppositely,this CSDS-induced reduction of the membrane expression of AMPA receptors was prevented by the knockout of caspase-1 or caspase-1 inhibitor,in which the expression of GluA1 and GluA2 were upregulated from(60.2±3.4)% and(63.9±3.7)% to(120.1±5.9)%and(112.6±9.6)%,respectively,while the total protein level of AMPA receptor subunits were not affected.On the other hand,a chronic intracerebroventricular injection of IL-1β,a downstream signal molecule of caspase-1,could induce depression-and anxiety-like behaviors in caspase-1 KO mice. CONCLUSION The caspase-1 can mediate the stress-induced depression-like behaviors by down-regulation of the membrane expression of AMPA receptors in hippocampus,the inhibition or knock-out of caspase-1can increase the expression of AMPA receptors in the membrane,thus reversing the depression-like behavior. Caspase-1 may serve as new target for depression therapy.
基金Supported by the National Natural Science Foundation of China(Topic 31572580)
文摘Neurotransmitters of the central nervous system were the important way to study the mechanism of anesthesia. The effect of different doses of xylazine anesthetic on the glutamate(Glu) and γ-aminobutyric-acid(GABA) were investigated and the mechanism of xylazine anesthetic on the central nervous system were explored in this study. A total of 88 rats were randomly divided into three groups, including normal saline control group, group with low dose of xylazine and group with high dose of xylazine.Cerebrum, cerebellum, hippocampus, thalamus and brainstem were collected. The results showed that the concentration of Glu in the hippocampus, thalamus and brainstem decreased first and then increased, but it increased first and then decreased in the cerebrum and cerebellum during the period of anesthesia. The concentration of GABA in the cerebrum, thalamus, brainstem and hippocampus increased first and then decreased. The results showed that xylazine inhibited Glu and promoted GABA with different dose dependence. The results and methods could provide guides for the clinical use of xylazine.
基金National Science and Technology Major Project of China (2015ZX09501003).
文摘OBJECTIVE Respiratory depression hinders the use of anaesthetics and sedative hypnotics.For emergency use,specific antagonists are currently administered to counteract respiratory depression.However,antagonists are often short-lasting and can have multiple unexpected side effects.A novel AMPA receptor modulator LCX001,synthesized by our Institute of Medicinal Chemistry,is expected to relieve suppressed respiration.To explore the mechanism and impact of LCX001 on protection against respiratory depression.METHODS LCX001 was tested to alleviate respiratory depression triggered by opioid,propofol and pentobarbital in the plethysmography recording.The acetic acid writhing and hot-plate tests were conducted to evaluate potential analgesic effect of LCX001.Binding assay and whole-cell recording were used to analyze the property of LCX001 on positive modulation.The function of AMPA receptors were determined by location of receptors inthe membrane and state of channel opening,and both processes were impressed by AMPA receptor regulatory proteins.According to the theory,the effect of LCX001 on the expression of stargazin was measured firstly by Western blotting.The variation of receptor surface location were observed by live cell imaging.The regulation on neuronal Ca2+and cell function was investigated intensively by Ca2+imaging to clarify mechanism of LCX001.RESULTS LCX001 effectively rescued and prevented opioid(fentanyl and TH-030418),propofol,and pentobarbitalinduced respiratory depression by strengthening respiratory frequency and minute ventilation by 30%-50% in rats.The acetic acid writhing test and hot-plate test revealed potent anti-nociceptive efficacy of LCX001 on increasing the inhibition rate and %MPE to 80% and 65% respectively,in contrast to some ampakines that did not affect analgesia.Furthermore,LCX001 potentiated[3 H]AMPA and L-glutamate binding affinity to AMPA receptors,and facilitated glutamateevoked inward currents in HEK293 cells stably expressing GluA2(R).At 10 mmol·L^(-1) glutamate evoked amplitudes,LCX001 at 100 μmol·L^(-1) increased the potency of glutamate induced currents by(1120 ± 60) pA,compared with that of(752 ± 35) pA in the control group.LCX001 also prominently promoted steady state/peak amplitude ratio.LCX001 significantly slowed down the desensitization rates of the AMPA ion channel,and inhibited current decay.Importantly,application of LCX001 generated a significant increase in GluA2(R) surface expression in a mechanism of stargazin up-regulation,and restrained opioidinduced abnormal intracel ular Ca2+load,which might participate in breathing modulation.CONCLUSION The typical positive modulatory impact and potential new mechanism of LCX001 might promote ampakines to be a therapeutic option for protection against respiratory depression.
文摘OBJECTIVE AMPA-subtype iono⁃tropic glutamate receptors(iGluRs)mediate fast excitatory synaptic transmission in the mammali⁃an central nervous system(CNS).It plays the key role in many central nerves disorder such as epilepsy,depression and schizophrenia.Star⁃gazin(STZ,also named TARP-γ2),as the first TARPs found in CNS,potentiates AMPAR activity by attenuating deactivation and desensitization,enhancing recovery from desensitization,and facilitating agonist affinity and efficacy.However,it is still not fully understanding howγ-2 modu⁃late AMPAR gating.METHODS AND RESULTS The desensitization for different mutation of AMPAR andγ-2 was compared.It was shown that the electric attraction was involved in the interaction of AMPAR andγ-2.In addition,the interaction of KGK motif in ligand binding domain and pre-M1 chain of AMPAR and EX1 ofγ-2 modulate AMPAR opening and desensitization.Substitution of these charged residues had sur⁃prisingly effects on AMPAR desensitization kinet⁃ics.CONCLUSION The electric attraction has two impacts on the channels gating process the first destablizing the receptor closed state and enabling the channel opening,the second pro⁃moting the channels entering desensitization state upon the channel opening.
基金Project supported by National Natural Science Fundation of China (No. 41130746).
文摘This article describes the characteristics of natural dusts, artificial dusts and industrial dusts, such as mineral phases, chemical components, morphological observation and size. Quartz and calcite are the main phases of natural dusts and industrial dusts with high SiO2, CaO and low K2O, Na2O on the chemical composition. Natural dusts are mainly irregular shaped and some particle aggregation made of small dusts on the surface of large dust. Industrial dusts are globular and blob-like, but artificial dusts are columnar and fibrous. The fine particles are mainly in the range of 0.3-5 μm,of which the dusts of less than 5 μm are over 99%.The dissolution and electrochemical action of dusts in glutamic acid liquor at the simulated human body temperature (37 ℃) in 32 hours were investigated. The changes of pH values and electric conductivity of those dusts were similar, increased slowly in first 8 hours, and then the pH values increased rapidly. The total amount of dissolved ions of K, Ca, Na, Mg was 35.4-429 mg/L, particularly Ca was maximal of 20-334 mg/L. The total amount of dissolved ions of Fe, Zn, Mn, Pb, Ba was 0.18-5.59 ppm and the Al, Si was 3.0-21.7 mg/L. Each element dissolved rapidly relatively in first 16 hours. The relative solubility order of dusts in glutamic acid are: wollastonite > serpentine > sepiolite, the cement plant industrial dusts > power plant industrial dusts, and natural dusts have similar solubility. The wollastonite and power plant industrial dusts have highest solubility, which have high content of CaO; this shows there are a poorer corrosion-resisting ability and lower bio-resistibility. Sepiolite and cement plant industrial dusts have lowest solubility, which have high content of SiO2; this shows there are a higher corrosion-resisting ability and stronger bio-resistibility.
