Amino Acids ; metabolism ; Animals ; Brain ; metabolism ; Electromagnetic Fields ; Electrophysiological Phenomena ; Glutamates ; metabolism ; Male ; Neurotransmitter Agents ; metabolism ; Pain ; physiopathology ; Pain Threshold ; Rats ; Rats, Sprague-Dawley ; gamma-Aminobutyric Acid ; metabolism

OBJECTIVE: To investigate the underlying molecular mechanisms by which silence information regulator (SIRT) 2 and glutaminase (GLS) in the amygdala regulate social behaviors in autistic rats. METHODS: Rat models of autism were established by maternal sodium valproic acid (VPA) exposure in wild-type rats and SIRT2-knockout ( SIRT2 ^-/-) rats. Glutamate (Glu) content, brain weight, and expression levels of SIRT2, GLS proteins and apoptosis-associated proteins in rat amygdala at different developmental stages were examined, and the social behaviors of VPA rats were assessed by a three-chamber test. Then, lentiviral overexpression or interference vectors of GLS were injected into the amygdala of VPA rats. Brain weight, Glu content and expression level of GLS protein were measured, and the social behaviors assessed. RESULTS: Brain weight, amygdala Glu content and the levels of SIRT2, GLS protein and pro-apoptotic protein caspase-3 in the amygdala were increased in VPA rats, while the level of anti-apoptotic protein Bcl-2 was decreased (all P<0.01). Compared with the wild-type rats, SIRT2 ^-/- rats displayed decreased expression of SIRT2 and GLS proteins in the amygdala, reduced Glu content, and improved social dysfunction (all P<0.01). Overexpression of GLS increased brain weight and Glu content, and aggravated social dysfunction in VPA rats (all P<0.01). Knockdown of GLS decreased brain weight and Glu content, and improved social dysfunction in VPA rats (all P<0.01). CONCLUSIONS The glutamate circulatory system in the amygdala of VPA induced autistic rats is abnormal. This is associated with the upregulation of SIRT2 expression and its induced increase of GLS production; knocking out SIRT2 gene or inhibiting the expression of GLS is helpful in maintaining the balanced glutamate cycle and in improving the social behavior disorder of rats.
Animals ; Rats ; Amygdala/metabolism* ; Autistic Disorder/metabolism* ; Behavior, Animal ; Disease Models, Animal ; Glutamates/metabolism* ; Glutaminase/metabolism* ; Sirtuin 2/metabolism* ; Social Behavior

This study aims to clarify the effect of Jingfang Mixture on the treatment of chronic urticarial and its mechanism, and investigate the regulatory effect of chronic urticaria on the metabolic disorder of endogenous metabolites in the blood. The mice were randomly divided into normal group, model group, and Jingfang Mixture group, and modeling and administration continued for 21 d. The changes in endogenous small molecules in rat serum were determined by ultra-high performance liquid chromatography-electrospray ionization-Q Exactive-Orbitrap-mass spectrometry(UHPLC-ESI-QE-Orbitrap-MS) metabolomics technology. The change trend of endogenous metabolites in rat serum was analyzed to find potential biomarkers. The results showed that Jingfang Mixture regulate 16 biomarkers, mainly including taurine, glutamate, succinic acid, docosahexaenoic acid, and arachidonic acid. Metabolic pathway analysis was carried out by MetaboAnalyst, and P<0.01 was taken as the potential key metabolic pathway. Ten metabolic pathways were closely related to the treatment of chronic urticarial by Jingfang Mixture, mainly involved in the glutamate metabolism, taurine and hypotaurine metabolism, arginine and proline metabolism, arachidonic acid metabolism, tricarboxylic acid cycle, unsaturated fatty acid biosynthesis, glutathione metabolism, phenylalanine metabolism, alanine, aspartic acid, and glutamate metabolism, and butyric acid metabolism. Glutamate metabolism and butyric acid metabolism involved more metabolic pathways than others. Therefore, it was speculated that Jingfang Mixture had a balanced regulating effect on the related metabolic pathways which caused the serum disorder in the rats with urticaria, and tended to regulate the metabolic differential to the normal level in the rats with urticaria. This paper provides references for studying the mechanism of Jingfang Mixture from the perspective of endogenous metabolites and metabolic pathways in vivo. At the same time, the endogenous substances explored in this paper can be used as important biomarkers for the prevention of urticaria.
Rats ; Mice ; Animals ; Chronic Urticaria ; Arachidonic Acid ; Butyric Acid ; Metabolomics/methods* ; Chromatography, High Pressure Liquid/methods* ; Biomarkers/metabolism* ; Taurine ; Glutamates

BACKGROUNDTumor cells can reduce the number of dendritic cells (DCs) in the tumor environment and cause DC dysfunction through autocrine or paracrine pathways. We sought to measure cyclooxygenase-2 (COX-2) expression in bombesin-inhibited DCs treated with theanine in vitro and to explore the protection and activation effects of theanine on DCs.

METHODSEnzyme-linked immunosorbent assay (ELISA), reverse transcription-polymerase chain reaction (RT-PCR), and Western blotting were used to analyze the effects of theanine on COX-2 expression and interleukin (IL)-12/IL-10 secretion of bombesin-treated DCs.

RESULTSDCs acquired an impaired phenotype as a result of bombesin treatment. Theanine increased the expression of mature DC surface molecules. The number of cell apoptosis with the treatment of bombesin and theanine significantly decreased, accounting for 15.9%, compared with 26.1% of cell apoptosis with bombesin. COX-2 expression in bombesin-treated DCs was inhibited by theanine in a dose-dependent manner. Theanine promoted DC secretion of IL-12. IL-12 levels reached (137.4 ± 4.9) pg/ml with theanine at 200 µmol/L. However, theanine inhibited the secretion of IL-10 in a dose-dependent manner. IL-10 levels were only (58.4 ± 6.9) pg/ml with theanine at 200 µmol/L.

CONCLUSIONTheanine inhibits the transcription and translation of COX-2 and regulates the balance of IL-10/IL-12 secretion in bombesin-inhibited DCs, leading to the recovery of a state of activation in DCs.

Bombesin ; pharmacology ; Cells, Cultured ; Cyclooxygenase 2 ; metabolism ; Dendritic Cells ; drug effects ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Glutamates ; pharmacology ; Humans ; Interleukin-10 ; metabolism ; Interleukin-12 ; metabolism

The amino acid L-glutamate is a major excitatory neurotransmitter in the central nervous system of vertebrates(1). NMDA (N-methyl-d-aspartate) is one of the L-glutamate receptor subtypes(2). During a critical period of early postnatal development, the visual cortex is susceptible to experience-dependent modification of neuronal responses. Recently, the activation of NMDA receptors has been supposed as a prerequisite for the induction of such modification(3). We therefore investigated developmental changes of NMDA receptors in the rat visual cortex and questioned whether they could be related to the visual development. We assessed the density of [(3)H]-NMDA receptor in the visual cortex of normally reared rate (Group I) and visually deprived rats (Group II) using quantitative autoradiography(4). The density of [(3)H]-NMDA receptor was significantly lower in Group II than in group I during the early postnatal period, and increased rapidly by postnatal 1 week and, decreased after postnatal 5 weeks. These results suggested that NMDA receptors may play a role in neuronal development in the visual cortex during the early postnatal period.
Animals ; Autoradiography ; Dark Adaptation ; Eyelids/surgery ; Glutamates/metabolism ; Glutamic Acid ; Light ; Rats ; Receptors, N-Methyl-D-Aspartate/*metabolism ; Visual Cortex/growth & development/*metabolism

OBJECTIVETo study the effects of theanine on dopamine (DA), 5-hydroxy tryptamine (5-TH) and glutamate receptor 2 (GluR2) mRNA, phospholipase-γ1 (PLC-γ1) mRNA in cerebral ischemia-reperfusion injury rats and explore the mechanism of protective effects of theanine on the induced brain injury by ischemia-reperfusion in rats.

METHODSAccording to random number table, a total of 56 sprague-dawley rats in SPF grade about six-week old and 100 - 120 grams weighting were divided into five groups according to the body weight levels: model group (n = 12), sham-operation group (n = 8), low theanine group (10 mg/kg), middle theanine group (30 mg/kg) and high theanine group (90 mg/kg). There were 12 rats in each of the theanine group. The rats in model group and sham-operation groups were given distilled water, and the rats in theanine groups were given corresponding theanine solution intragastrically for fifteen days. Then the cerebral ischemia-reperfusion injury was established by middle cerebral artery occlusion (MCAO). The score of neurological behavior was evaluated at the 3rd and 24th hours after reperfusion. Rats were sacrificed at 24 hours after reperfusion, the concentrations of DA, 5-HT and theanine in rats brain following ischemia-reperfusion were determined. At the same time, we determined the levels of reactive oxygen species (ROS) and activities of catalase (CAT) in mitochondria of brain. The expressions of GluR2 mRNA and PLC-γ1 mRNA in rat brain were examined by reverse transcription polymerase chain reaction (RT-PCR) technique.

RESULTSThe score of neurological behavior of rats in model group, theanine-low, middle, high dose groups at the 3rd hour was 6.000 ± 0.926, 4.100 ± 0.738, 3.444 ± 0.726 and 2.250 ± 0.886 respectively (F = 29.70, P < 0.01), and the score at the 24th hour in these groups was 6.625 ± 0.916, 5.000 ± 0.817, 3.667 ± 0.707 and 2.625 ± 0.916 respectively(F = 34.68, P < 0.01). The concentration of DA in model group, theanine-low, middle, high dose groups and sham-operation group was (10.26 ± 1.12), (12.48 ± 1.09), (14.55 ± 0.94), (15.97 ± 0.92) and (11.98 ± 0.63) µg/g respectively (F = 43.76, P < 0.01). The concentration of 5-HT in these groups was (1.091 ± 0.160), (0.818 ± 0.101), (0.571 ± 0.050), (0.453 ± 0.111) and (0.863 ± 0.063) µg/g respectively (F = 48.68, P < 0.01). The level of ROS was (3.072 ± 0.503), (1.331 ± 0.268), (1.295 ± 0.061), (0.804 ± 0.200) and (2.158 ± 0.218) U×min⁻¹×mg⁻¹ (F = 80.82, P < 0.01) respectively and the activities of CAT in these groups were (4.880 ± 1.121), (8.405 ± 1.356), (9.535 ± 2.511), (15.090 ± 4.054) and (21.260 ± 6.054) U/g respectively (F = 28.58, P < 0.01). The expressions of GluR2 mRNA were 0.842 ± 0.020, 1.063 ± 0.100, 1.170 ± 0.152, 1.254 ± 0.131 and 1.012 ± 0.056 respectively (F = 9.23, P < 0.01). The expressions of PLC-γ1 mRNA in these groups were 0.737 ± 0.090, 0.887 ± 0.045, 0.963 ± 0.025, 0.991 ± 0.049 and 0.867 ± 0.079 respectively(F = 10.24, P < 0.01).

CONCLUSIONTheanine has a protective effect on the induced brain injury by ischemia-reperfusion in rats, which might be associated with its interaction with monoamine neurotransmitters and up-regulating the expressions of GluR2 mRNA and PLC-γ1 mRNA.

Animals ; Biogenic Monoamines ; metabolism ; Brain ; drug effects ; metabolism ; Brain Ischemia ; genetics ; metabolism ; Glutamates ; pharmacology ; Male ; Neurotransmitter Agents ; pharmacology ; Phospholipase C gamma ; genetics ; metabolism ; RNA, Messenger ; genetics ; Rats ; Rats, Sprague-Dawley ; Receptors, AMPA ; genetics ; metabolism ; Reperfusion Injury ; genetics ; metabolism

This study was aimed to investigate the mechanisms underlying the modulation effect of Mas-related gene (Mrg) C receptors (MrgC) on morphine tolerance. Saline, morphine (20 μg), morphine plus bovine adrenal medulla 8-22 (BAM8-22, 1 nmol) or (Tyr(6))-2-MSH-6-12 (MSH, 5 nmol) were administered intrathecally in rats for 6 days. Pain-related molecules in the spinal cord and dorsal root ganglion (DRG) were examined using Western blot, immunocytochemistry and RT-PCR techniques. The results showed that intrathecal administration of the selective MrgC receptor agonists (BAM8-22 or MSH) remarkably attenuated or abolished chronic morphine-evoked reduction in glutamate transporters (GLAST, GLT-1 and EAAC1) in the spinal cord and increase in neuronal nitric oxide synthase (nNOS) in the spinal cord as well as DRG. In addition, MrgC receptor-like immunoreactivity (IR) was detected in superficial laminae of the spinal cord. Chronic morphine induced significant increases in MrgC receptor-IR in the spinal cord and MrgC receptor mRNA levels in DRG. These results suggest that the modulation of pro-nociceptive mediators in the spinal cord and DRG underlies the inhibition of morphine tolerance by MrgC receptor activation.
Amino Acid Transport System X-AG ; metabolism ; Animals ; Drug Tolerance ; Ganglia, Spinal ; metabolism ; Glutamates ; Morphine ; pharmacology ; Nitric Oxide Synthase Type I ; metabolism ; Pain ; Pain Measurement ; Peptide Fragments ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Receptors, G-Protein-Coupled ; metabolism ; Spinal Cord ; metabolism

Sulpiride, a selective antagonist for adenylate cyclase-independent dopamine receptors, was administrated to 25 patients with blepharospasm and oromandibular dystonia(Meige's syndrome). Of the 25, 7 patients (28%) exhibited marked and lasting improvement with sulpiride and 12 patients (48%) showed mild or transient improvement. This favorable therapeutic response to sulpiride suggests that striatal glutamate underactivity may play a role in the pathophysiology of Meige's syndrome as a primary or secondary defect.
Adult ; Aged ; Basal Ganglia Diseases/*drug therapy ; Corpus Striatum/metabolism ; Dopamine/metabolism ; Female ; Glutamates/metabolism ; Glutamic Acid ; Human ; Male ; Meige Syndrome/*drug therapy/metabolism ; Middle Age ; Sulpiride/*therapeutic use

By using Fura-2/AM, the effects of magnesium (Mg2+) on the glutamate-induced increase of intracellular free calcium ([Ca2+]i) in the cultured hippocampal neurons and the features were investigated by integrated photoelectric detecting system. The experiments were designed to three groups (The drug was spit to the cells for 20 s): Group A receiving 1 x 10(-5) mol/L glutamate; Group B receiving 1 x 10(-5) mol/L glutamate and 1 x 10(-5) mol/L Mg2+ simultaneously; Group C receiving 1 x 10(-5) mol/L glutamate again after [Ca2+]i in group B back to the baseline. The results showed that in group A, [Ca2+]i was obviously increased. In group B, the changes in [Ca+] i and the peak value were significantly decreased. Moreover, the elevation of Phase 1 was slowed down and Phase 2 was shortened to some extent, and the plateau phase between them was relatively prolonged. In group C, calcium oscillation similar to that in group A occurred, but both the Phase 1 and Phase 2 were shortened and the delta[Ca2+]i was slightly decreased. It was suggested that Mg2+ could quickly inhibit the rise of [Ca2+]i induced by glutamate in the cultured hippocampal neurons in rats.
Animals ; Animals, Newborn ; Biological Transport, Active ; drug effects ; Calcium ; metabolism ; Cells, Cultured ; Fura-2 ; pharmacology ; Glutamates ; pharmacology ; Hippocampus ; cytology ; metabolism ; Magnesium ; pharmacology ; Neurons ; cytology ; metabolism ; Rats ; Rats, Sprague-Dawley

AIMTo investigate the effect of iptakalim (Ipt), a novel ATP-sensitive potassium channel opener (KATPCO), on astrocyte glutamate uptake activity. The mechanism of action involved was also examined.

METHODSPrimary cultures of astrocytes were prepared from cerebral cortexes of 1 to 2 days old Sprague-Dawley rats. Cultures were preincubated with iptakalim of various concentrations with the absence or presence of 6-hydroxydopamine (6-OHDA, 50 micromol x L(-1)). Then, the cells were treated with pinacidil (10 micromol x L(-1), K+ channel opener) instead of iptakalim and pretreated with glibenclamide (20 micromol x L(-1), ATP-sensitive K+ channel inhibitor) before pinacidil or iptakalim was added into the medium so that the mechanism of action of iptakalim could be analysed. Astrocyte glutamate uptake activity was determined by intracellular concentration of 3H labeled D,L-glutamate, using isotope techniques.

RESULTSBoth iptakalim and pinacidil were shown to increase glutamate uptake activity of astrocytes and reverse inhibitory effect induced by 6-OHDA. But the increased and reversed effects of iptakalim or pinacidil on astrocytic glutamate uptake were found to be completely antagonized by glibenclamide.

CONCLUSIONThese data indicated that iptakalim can enhance astrocytic glutamate uptake activity due to its K+ channel opening properties and lessen glutamate excitotoxicity. Iptakalim may be useful for the therapy of Parkinson's disease.

Animals ; Animals, Newborn ; Astrocytes ; drug effects ; metabolism ; Cells, Cultured ; Cerebral Cortex ; cytology ; Glutamates ; metabolism ; Glyburide ; antagonists & inhibitors ; Neuroprotective Agents ; pharmacology ; Oxidopamine ; antagonists & inhibitors ; Pinacidil ; pharmacology ; Propylamines ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Vasodilator Agents ; pharmacology