Glu Content Research Articles

The glutaminase (CgGLS-1) mediates anti-bacterial immunity by prompting cytokine synthesis and hemocyte apoptosis in Pacific oyster Crassostrea gigas

Glutaminase, an amidohydrolase enzyme that hydrolyzes glutamine to glutamate, plays crucial roles in various immunomodulatory processes such as cell apoptosis, proliferation, migration, and secretion of cytokines. In the present study, a glutaminase homologue (designated as CgGLS-1) was identified from Pacific oyster Crassostrea gigas, whose open reading frame was of 1836 bp. CgGLS-1 exhibited high sequence identity with vertebrate kidney-type GLS, and closely clustered with their homologues from mollusc C. virginica. The enzyme activity of recombinant CgGLS-1 protein (rCgGLS-1) was estimated to be 1.705 U/mg. CgGLS-1 mRNA was constitutively expressed in all the tested tissues of oysters, with the highest expression level in hemocytes. CgGLS-1 mRNA expression in hemocytes was significantly up-regulated and peaked at 6 h (2.07-fold, p < 0.01) after lipopolysaccharide (LPS) stimulation. The CgGLS-1 protein was mainly distributed in the cytoplasm with a significant co-location with mitochondria in oyster hemocytes. The content of Glu in the oyster serum was significantly decreased after the inhibition of CgGLS-1 using specific inhibitor Bis-2- [5-(phenyl acetamido)-1,3,4-thiadiazol-2-yl] ethyl sulfide (BPTES), and the expression levels of CgmGluR6, CgAP-1, cytokines CgIL17-5 and CgTNF-1 were significantly decreased after BPTES and LPS stimulation. The transcripts of CgCaspase3 as well as the apoptosis index of hemocytes were also decreased. These results collectively suggest that CgGLS-1 is the enzyme to synthesize Glu in oyster, which can modulate anti-bacterial immunity by regulating the secretion of pro-inflammatory cytokines CgIL17-5 and CgTNF-1, as well as hemocyte apoptosis.

Rhubarb anthraquinone glycosides protect against cerebral ischemia‐reperfusion injury in rats by regulating brain–gut neurotransmitters

Rhubarb anthraquinone glycosides (RAGs) have been proven to have significant therapeutic effects on ischemic stroke, and this effect may be related to the microbiome-gut-brain axis. In this study, an HPLC-FLD method was established to measure brain-gut neurotransmitters of rats with cerebral ischemia-reperfusion injury (CIRI), to explore whether the mechanism of RAGs against CIRI is related to the microbiome-gut-brain axis. A Shimadzu ODS-3 C18 column was used for chromatographic separation, and 5-hydroxytryptamine (5-HT), 5-hydroxy indole acetic acid (5-HIAA), glutamic acid (Glu), aspartic acid (Asp), and γ-aminobutyric acid (GABA) were determined simultaneously. The results showed that there is an excellent linear relationship (R2 ≥ 0.9990) and a high separation degree in the HPLC-FLD method. Whereas the contents of Asp and Glu in the brain and colon increased (p < 0.05), the contents of 5-HT, 5-HIAA, and GABA in the brain and colon decreased (p < 0.05) after CIRI. RAGs could effectively reduce the contents of Asp and Glu (p < 0.05), and increase the contents of 5-HT, 5-HIAA, and GABA in the brain and colon (p < 0.05). Combined with the previous experimental results, we can speculate that RAGs can regulate intestinal flora disorder caused by CIRI, and then regulate the imbalance between the release and decomposition of neurotransmitters caused by intestinal flora disorder.

Effects of different levels of Hermetia illucens larvae meal on performance, egg quality, yolk fatty acid composition and oxidative status of laying hens

To investigate the supplemental effects of Hermetia illucens larvae meal (HILM) on the production, egg quality, yolk fatty acid composition, egg amino acid content, oxidative status, and immune indexes of laying hens. A total of 432 Xuefeng black-bone chickens (45-week-old) were randomly assigned to 4 treatments with 6 replicates per treatment and 18 hens in each replicate. The laying hens were fed the basal diet supplemented with 0%, 1%, 3%, and 5% HILM (CON, HILM-1, HILM-3, and HILM-5, respectively) for 56 d. The experimental diets were isonitrogenous and isoenergetic. The highest egg weight and Haugh unit were obtained with 3% HILM supplementation, but the HILM-3 or HILM-5 supplementation have negative effect on the eggshell thickness, yolk index, and albumen height during the early stage of the experiment. The HILM supplementation linearly or quadratically (p < .05) increased the C14:0, C17:0, C18:2n6c, C20:2 contents of yolk, the Glu, Val, Met, Phe, and Leu contents of egg, the T-SOD and CAT activities, and the NDV-Ab and AIV-Ab levels of plasma. With increasing supplementation of HILM in the basal diet, FCR, the C16:0 and C16:1 contents of yolk, MDA content and IL-2 level of plasma decreased both linearly or quadratically (p < .05). In conclusion, Hermetia illucens larvae meal can be a suitable alternative protein source for Xuefeng black-bone chicken. Dietary supplementation of 3% HILM in basal diets may be a feasible means of effectively increasing the production performance of laying hens, and partially enhanced hens’ antioxidant capability and immune function. HIGHLIGHTS Supplementation of 1% HILM had no effect on laying hens, and supplementation of 3% HILM increased the egg weight and Haugh unit. Supplementation of 3% HILM or 5% HILM have a negative effect on the eggshell thickness, yolk index, and albumen height during the early stage of the experiment. Supplementation of 3% HILM increased the C14:0, C17:0, and C20:2 contents of yolk, the Glu, Val, Met, Phe, and Leu contents of egg. The plasma antioxidant status and immune response improved by dietary addition of HILM at 3% levels.

Penicillium expansum – Induced release of branched-chain volatile compounds in apple fruit by increasing amino acids accumulation

Abstract Amino acids (AAs) play a critical role in resistance response and biosynthesis of volatile compounds (VOCs) in fruit. In this study, we inoculated apple fruits (cv. Delicious) with Penicillium expansum to investigate the effect of different AA accumulation on the biosynthesis of branched-chain VOCs at different stages of colonization. Generally, infection significantly increased the total AAs in fruit by 38.65 %. Of the 17 AAs detected in fruit, the contents of Asp, Val, Leu, Ala, Ser, Cys, Thr, His, Agr, Glu, Met, Gly, and Pro increased in the early and middle stages of colonization ( 6 DAI). Moreover, infection promoted higher activities of PDC and PDH involved in branched-chain VOCs biosynthesis, leading to increased contents of branched-chain VOCs. These results suggest that P. expansum increases AA’s accumulation and release of branched-chain VOCs in apple fruit.

Nonvolatile taste compounds of Shanghai smoked fish: A novel three stages control techniques.

In this work, the effect of processing stages including first soaking (FS), frying after first soaking (FFS), and second soaking (SS) on nonvolatile taste compounds of Shanghai smoked fish was investigated using high‐performance liquid chromatography (HPLC) and automatic amino acid analyzer. Results showed that the contents of free amino acids (FAAs) ranged from 396.94 to 585.79 mg/100 g and 5′‐inosine monophosphate (IMP, as main umami nucleotide) from 215.91 to 284.56 mg/100 g in Shanghai smoked fish, respectively. Moreover, the contents of Glu and Gly as main umami amino acids ranged from 1.64 to 107.32 mg/100 g and 61.61 to 108.88 mg/100 g, respectively. TAV values of IMP, Asp, and Glu in Shanghai smoked fish reached 11.38, 2.73, and 21.46, respectively. The obvious difference could be observed using principal component analysis (PCA) in three processing stages of Shanghai smoked fish. Therefore, probing into the nonvolatile flavor of Shanghai smoked fish could not only enrich the theoretical basis of flavor chemistry in freshwater fish fields, but probe into the formation mechanisms of taste compounds in further study.

Effect of Panax japonicus saponin Ⅳa on alleviating nonalcoholic steatohepatitis by regulating miR-17-5p/MFN2 signaling pathway

To study the effect of Panax japonicas saponin Ⅳa(SPJ-Ⅳa) on nonalcoholic steatohepatitis(NASH) through miR-17-5 p/MFN2 signaling pathway. The nonalcoholic steatohepatitis model was induced by a high-fat diet combined with CCl_4 in Balb/c male mice. The mouse serum and liver were collected, the body weight and liver weight were measured, the liver index was calculated, and the serum biochemical indicators alanine amino transferase(ALT), triglyceride(TG), and glucose(Glu) were measured. The morphological changes in the liver were detected by HE and Masson staining, Real-time PCR was used to detect lipid metabolism-related genes, inflammation-related genes interleukin-6(IL-6) and interleukin-1β(IL-1β), miR-17-5 p and MFN2 expressions, and Western blot was used to detect MFN2 protein expression level. Compared with the normal control group, the liver index in the HFD+CCl_4 group was significantly increased, and the contents of ALT, TG, and Glu were significantly increased; the morphology showed obvious steatosis and collagen fiber deposition; mRNA expression levels of lipid metabolism-related genes, inflammation-related genes and miR-17-5 p increased significantly, the mRNA expression level of MFN2 decreased significantly, and the protein level of MFN2 decreased. After intervention with SPJ-Ⅳa, the levels of ALT, TG and Glu decreased, morphological steatosis decreased, collagen fiber deposition decreased, and mRNA expression levels of lipid metabolism-related genes, inflammation-related genes and miR-17-5 p decreased. The mRNA expression level of MFN2 increased, and the protein level of MFN2 also increased. The results of this study indicated that miR-17-5 p/MFN2 signaling pathway may be involved in the occurrence and development of NASH, and SPJ-Ⅳa had a protective effect on NASH, its mechanism may be related to the regulation of miR-17-5 p/MFN2 signaling pathway.

Ferulic acid alleviates lipopolysaccharide-induced acute liver injury in Megalobrama amblycephala

Ferulic acid (FA) is a common phenolic compound that possesses antioxidant, anti-bacterial, anti-inflammatory, anti-hyperlipidemic, and immune-enhancing properties. Here, we established an oxidative stress and inflammatory model in blunt snout bream by intraperitoneally injecting lipopolysaccharide (LPS, 30 mg/kg BW (body weight)) to explore the effects of FA on oxidative stress, as well as its underlying protective mechanisms. Fish (96.43 ± 0.62 g) were randomly distributed into four groups: (1) saline injection after saline gavage, (2) LPS injection (30 mg/kg BW) after saline gavage, (3) LPS injection (30 mg/kg BW) after FA gavage (50 mg/kg BW), (4) LPS injection (30 mg/kg BW) after FA gavage (100 mg/kg BW). LPS injection induced liver damage at 24 hpi (hour post injection), with evidently increased hepatocyte apoptosis rates, as determined by TUNEL staining, and increased lysosomes, vacuoles, and visibly dilated hepatic sinusoids, as determined by hematoxylin-eosin (HE) staining. Moreover, plasma AST activity and HDL content significantly increased, and the TP, TC, TG, GLU, and C4 contents significantly decreased in the LPS-treated group. However, FA treatment showed lower apoptosis rates and fewer changes in liver structure than the LPS-treated group, which confirmed the replenishing effects of FA on LPS-induced liver damage. Moreover, plasma parameters including GLU, TP, AST, and C4, were effectively improved after 50 and/or 100 mg/kg BW FA administration. Furthermore, FA gavage (50 mg/kg BW) significantly decreased ROS content in blood. Our results also demonstrated that FA gavage enhanced hepatic antioxidant enzyme activities and increased GSH contents at 24 hpi to resist LPS-induced liver damage. Particularly, FA gavage (50 mg/kg BW and 100 mg/kg BW) significantly increased the levels of GSH and GST, whereas FA gavage at 50 mg/kg BW significantly increased SOD and GR activities. Additionally, FA gavage at 100 mg/kg BW increased GPx activity. Furthermore, the 50 mg/kg BW FA treatment also significantly increased the expression of sod, cat, and gpx mRNA. FA gavage (50 mg/kg BW and 100 mg/kg BW) also significantly decreased the contents of pro-inflammatory cytokines such as TNF-α and IL-1β under LPS stimulation at 96 hpi. Overall, the present study clarified the effect of sustained FA administration on LPS-induced oxidative stress, as well as its underlying protective mechanisms, thereby establishing a theoretical basis to further characterize the effects of FA as an antioxidant fish feed additive.

Effect of wrist-ankle acupuncture on the expression of glutamate and NMDA receptor of the spinal dorsal horn in rats with neuropathic pain

To observe the effect of wrist-ankle acupuncture (WA) stimulation at "R4"- "R5" - "R6" on the expression of glutamate (Glu) and phosphorylated protein NMDAR1(p-NMDAR1) of the spinal dorsal horn in spared nerve injury (SNI) rats, so as to explore its mechanism underlying improvement of SNI. A total of 36 SD rats were randomly divi-ded into sham operation, model and WA groups, with 12 rats in each group. The SNI procedure comprised an axotomy and ligation of the tibial and common peroneal nerves leaving the sural nerve intact. Rats of the WA group were treated by acupuncture at "R4"-"R5"-"R6" points from the 5th day to the 14th day after modeling. The mechanical pain thresholds were measured before and 5, 10 and 14 d after SNI, respectively. The cold allodynia was dectected by Acetone solution dropped onto the lateral plantar surface of the paw. Glu content and p-NMDAR1 expression of spinal dorsal horn were detected by 1H-MRS, ELISA and immunohistochemistry Methods. Compared with the sham operation group, the mechanical pain threshold of the model group was significantly decreased (P<0.01), the duration of cold stimulation foot contraction was increased (P<0.01), and the Glu content and p-NMDAR1 expression in the spinal dorsal horn were significantly increased (P<0.05, P<0.01). After WA intervention, the mechanical pain threshold was significantly increased (P<0.01), the duration of cold stimulation was significantly shortened (P<0.01), and Glu content and p-NMDAR1 protein expression of spinal dorsal horn were decreased significantly (P<0.05, P<0.01) in the WA group compared with the model group. WA can reduce pain sensitivity in rats with neuropathic pain, possibly by inhibiting the expression of Glu and p-NMDAR1 in the spinal dorsal horn.

Crosstalk between GABA and ALA to improve antioxidation and cell expansion of tomato seedling under cold stress

Cold stress inhibits plant growth and ultimately affects yield formation. Exogenous 5- aminolevulinic acid (ALA) can improve tomato cold tolerance and promote plant growth. It significantly up-regulated glutamate decarboxylase gene (SlGAD4) expression, which was involved in gamma-aminobutyric acid (GABA) synthesis. Whether the GABA was involved in ALA-regulated tomato cold tolerance and plant growth was unclear. Thus, this study aimed to explore the effects of exogenous ALA and GABA on endogenous ALA and GABA synthesis. The roles of ALA and GABA on regulating the antioxidation and cell morphological changes related to plant growth in tomato leaves were further explored. And the internal relationship between ALA and GABA in increasing tomato cold tolerance was also determined. Results showed that cold stress increased the glutamate (Glu) and GABA contents and reduced the ALA content. The exogenous ALA- or GABA-treated plants demonstrated decreased Glu content and increased GABA or ALA contents. Exogenous ALA or GABA treatment promoted the expansion of upper epidermal (UEP) and palisade parenchymal (PA) cells and up-regulated the xyloglucan endotransglucosylase/hydrolases gene (SlXTH23) expression in tomato leaves. Exogenous ALA or GABA significantly alleviated cold-induced tomato membrane lipid peroxidation and enhanced C-repeat binding factors gene (SlCBF2) expression and superoxide dismutase (SOD), catalase (CAT), APX and GR activities. Inhibiting endogenous GABA with 3-mercaptopropionic (3-mp) dramatically decreased the size of UEP and PA cells and reduced SOD and CAT activities. It also aggravated the membrane peroxidation damage, which notably weakened the alleviated effects of exogenous ALA. Inhibiting endogenous ALA with gabaculine (gaba) partly inhibited the alleviated effects of exogenous GABA. These findings indicated that spray with exogenous ALA or GABA could increase endogenous ALA and GABA levels in tomato leaves. In addition, endogenous GABA and ALA could be mutually converted through Glu. Exogenous ALA and GABA promoted cell expansion, stimulated the antioxidant system and might enhance tomato cold tolerance via endogenous GABA signal and the C-repeat binding factor regulation pathway, thereby alleviating cold inhibited plant growth. In conclusion, GABA crosstalk with ALA improved tomato cold stress tolerance and promoted plant growth by regulating antioxidants and cell expansion.

Reduction in dietary lysine increases muscle free amino acids through changes in protein metabolism in chickens

Taste is crucial to meat quality, and free Glu is an important taste-active component in meat. Our recent study showed that the short-term feeding of a low-Lys diet increases the concentration of free Glu and other free amino acids in chicken muscle and improves its taste. Here, we investigated the mechanisms by which the feeding of a low-Lys diet increases free Glu in chicken muscle. Two groups (n = 10 per group) of 28-day-old female Ross strain broiler chickens were fed diets with a graded Lys content of 90% or 100% of the recommended Lys requirement (according to National Research Council [1994] guidelines) for 10 D. Free amino acid concentrations and the mRNA abundance of protein metabolism–related genes were measured in breast muscle, and breast muscle metabolome analysis was conducted. Free Glu in muscle was increased by 51.8% in the Lys 90% group compared with the Lys 100% group (P < 0.01). Free threonine, glutamine, glycine, valine, isoleucine, leucine, tyrosine, phenylalanine, histidine, and 3-methyl-histidine concentrations in breast muscle were also increased in the Lys 90% group (P < 0.05). Metabolome analysis also showed that free amino acids were increased in the Lys 90% group. The mRNA abundance of μ-calpain, caspase-3, and 20S proteasome C2 subunit were increased in the Lys 90% group (P < 0.05). Moreover, the free Glu concentration in muscle was correlated with mRNA abundance of μ-calpain (r = 0.74, P < 0.01), caspase 3 (r = 0.69, P < 0.01), 20S proteasome C2 subunit (r = 0.65, P < 0.01), and cathepsin B (r = 0.52, P < 0.05). Our study suggests that the feeding of a low-Lys diet to chickens increased the free Glu content of breast muscle by promoting protein degradation.

Sevoflurane inhibits neuronal apoptosis and expressions of HIF-1 and HSP70 in brain tissues of rats with cerebral ischemia/reperfusion injury.

To observe the influences of sevoflurane on neuronal apoptosis and expressions of hypoxia-inducible factor 1 (HIF-1), and heat-shock protein 70 (HSP70) in brain tissues of rats with cerebral ischemia/reperfusion (I/R) injury. A total of 60 Sprague-Dawley rats were selected and divided into sham-operation group (Sham group, n=20), cerebral I/R model group (Model group, n=20), and 3% sevoflurane treatment group (Sevoflurane group, n=20). The rats in each group received neurological scoring, and the blood and brain tissues were collected to detect the concentrations of serum K+, Na+ and glucose (Glu). Enzyme-linked immunosorbent assay (ELISA) was adopted to measure the levels of inflammatory factors [tumor necrosis factor-β (TNF-β) and interleukin-6 (IL-6)] and oxidative stress [catalase (CAT), malondialdehyde (MDA) and superoxide dismutase (SOD)]. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay was performed to determine the nerve cell apoptosis in the brain tissues. The gene and protein expressions of Caspase-3, HIF-1, and HSP70 in the brain tissues were measured via quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR) and Western blotting. In Sevoflurane group, the content of serum Glu and Na+ was decreased markedly, that of K+ was increased notably, and the levels of TNF-β, IL-1 and IL-6 were lowered remarkably compared with those in Model group (p<0.05). Moreover, the neurological score was reduced evidently (p<0.05). Model group had significantly strengthened the activity of MDA and CAT and decreased SOD content, while Sevoflurane group exhibited the opposite results. TUNEL staining showed that there were distinctly more apoptotic cells that were dominated by glial cells in Model group and fewer apoptotic cells in Sevoflurane group. It was indicated in gene assay that the messenger ribonucleic acid (mRNA) expression levels of HIF-1, HSP70, and Caspase-3 in Model group were remarkably higher than those in Sham group and Sevoflurane group (p<0.05). According to the results of Western blotting, the protein expressions of HIF-1 and HSP70 in Sevoflurane group were markedly lower than those in Model group. Sevoflurane can reduce the content of inflammatory factors, inhibit apoptosis, and reduce the expressions of HIF-1 and HSP70 in the case of cerebral I/R injury, thus exerting protective effects on rats with cerebral I/R injury.

Glutamate promotes sweet potato storage root swelling by enhancing starch accumulation

Storage root (SR) development is a crucial factor for producing high yields of sweet potato. To elucidate the mechanisms of SR development, we examined different glutamate (Glu) contents using pot experiments. The Glu acts as an efficient indicator of plant root size and provides a measurable and controllable factor for exploring plant root growth. The present study aimed to evaluate the effects of 0.5, 1.0, 3.0 and 5.0 mM Glu on sweet potato swelling and starch metabolic pathways in the Sushu-16 variety. Then, morphological observations were conducted and physiological characterizations, including starch, sucrose and hormone contents were measured under the different Glu concentrations. RNA-seq was used for gene expression studies in SRs and validated using RT-qPCR. The latter confirmed that starch metabolism was up-regulated and that Glu applications increased the starch content in SR, which enhanced SR swelling. Glu, especially 3 mM Glu, enhanced SR production and starch biosynthesis in sweet potato. These results increased the understanding of the molecular physiology of SR formation in sweet potato and highlighted the future prospects for SR swelling through Glu applications.

Aqueous extracts of Lindera aggregate (Sims) Kosterm leaves regulate serum/hepatic lipid and liver function in normal and hypercholesterolemic mice

The leaves of Lindera aggregate (Sims) Kosterm. are traditionally used as healthy tea for the prevention and treatment of hyperlipidemia in Chinese. The aim of this study was to evaluate the antihyperlipidemic effects and potential mechanisms of the aqueous extracts from L. aggregate leaves (AqLA-L) on normal and hypercholesterolemic (HCL) mice. HCL mice were induced by high fat diet (HFD) and orally administrated with or without AqLA-L for ten days. The results showed that AqLA-L (0.3, 0.6, 1.2 g/kg) significantly reduced serum TG, ALT, but elevated fecal TG in normal mice. AqLA-L (0.3, 0.6, 1.2 g/kg) also remarkably lowered serum TC, TG, LDL, N-HDL, ALT, GLU, APOB, hepatic GLU and increased serum HDL, APOA-I, fecal TG levels in HCL mice. These results revealed that AqLA-L treatment regulated the disorders of the serum lipid and liver function, reduced hepatic GLU contents both in normal and HCL mice. The potential mechanisms for cholesterol-lowering effects of AqLA-L might be up-regulation of cholesterol 7-alpha-hydroxylase (CYP7A1) and ATP-binding cassette transporter A1 (ABCA1), as well as down-regulation of 3-hydroxy-3-methylglutaryl CoA reductase (HMGCR). The data indicated that AqLA-L has potential therapeutic value in treatment of hyperlipidemia with great application security.

Rice grains alleviate cadmium toxicity by expending glutamate and increasing manganese in the cadmium contaminated farmland

The accumulation of cadmium (Cd) in rice grains is closely associated with the content of mineral nutrients and amino acid metabolism, but the causal link among them is unclear. Profiles of amino acids (AAs) and quantities of essential nutrients in grains from early and late rice cultivars grown at four sites with different Cd levels were analyzed in the present study. Hazard quotients (HQs) for consumers by intake of rice from late cultivars were much higher than that from early cultivars at sites with soil Cd content of 0.25, 0.61 and 0.84 mg kg−1. Cadmium accumulation in grains resulted in a sharp reduction of total essential AAs and non-essential AAs in both early and late rice cultivars. High-Cd-accumulating (HCA) cultivars had significantly higher level of glutamate (Glu) than low-Cd-accumulating (LCA) cultivars when rice Cd content was less than 0.20 mg kg−1. However, Glu level in grains dramatically declined with the accumulation of Cd, which subsequently leaded to the reduction of other AAs. Cadmium content was well predicted by five amino acids (i.e., Glu, Alanine, Phenylalanine, Glycine and Threonine) or four essential elements (Ca, Fe, Mn and Zn) when rice Cd was less than 0.80 mg kg−1. Amino acids played more important roles than nutrients in Cd accumulation. When Cd content was in the range of 0.40–1.16 mg kg−1, the Mn content in rice increased significantly with the increase of Cd content, while the Glu content dropped down synchronously. Remarkably, the ratio between Mn and Glu displayed the highest direct path coefficient on Cd accumulation than any single cation or amino acid. These results indicate that high capacity in synthesizing Glu and concentrating Mn is the determinant factor for Cd accumulation in rice grains, and abundant Glu in aleurone layer may alleviate Cd toxicity by forming Glu-Cd complex.

Gender differences in the pool of free amino acid neurotransmitters in Krushinsky-Molodkina rats

The study of the role of neurotransmitter systems in the pathogenesis of epilepsy is one of the priorities of epileptology. New data on the functions of free neurotransmitter-like amino acid in the central nervous system are of the greatest importance and determine the prospects for the development of novel effective anticonvulsants. It is widely believed in clinical medicine that epilepsy has distinct gender characteristics. The aim of this study was to investigate the gender peculiarities in the content of neurotransmitter amino acids in the brain of Krushinsky-Molodkina (KM) rats, which were used as model organisms for the study of genetically induced audiogenic epilepsy. The content of Asp, Glu, GABA, Gly, and Tau of the medulla oblongata, hippocampus and cerebral cortex were determined using high-performance liquid chromatography (HPLC) in intact KM rats, KM rats exposed to a series of epileptiform seizures, and Wistar rats (control group). Both the Wistar and KM rats had gender distinctions in the distribution of free amino acids among the investigated brain parts. The audiogenic epilepsy was characterized by smoothing gender differences as well as differences between the concentrations of free amino acids in the cortex and medulla oblongata, specific for Wistar rats. The changes observed in male rats after the set of seizures included the increase in GABA concentration and a decrease in the Gly level in all investigated brain parts, as well as the decrease of the Tau content in the cortex and hippocampus. At the same time, the Glu content in cortex increased, while the Asp level decreased. After 6 days of audiogenic stimulations the female KM rats demonstrated the increase in the Glu level in all investigated brain parts, the increase in Gly and Asp levels in hippocampus, and no changes in the GABA content. Thus, after the set of epileptiform seizures the KM rats achieved a new steady state of the studied amino acids pool, which differed in males and females. In this case, gender differences significantly changed after the seizures.

Protective effects and mechanisms of Xingnaojing Injection on early global brain ischemic-induced deep coma in rats

To study the protective effect of Xingnaojing Injection on early global brain ischemia-induced deep coma in rats. Methods: The deep coma model was induced by global brain ischemia by using four-vessel occlusion method in male SD rats. According to the body weight, the rats were randomly divided into 8 groups: a model control group, three different dose of Xingnaojing Injection (1.8, 3.6 and 5.4 mL.kg-1) groups, a Xingnaojing Injection (3.6 mL.kg-1) plus PI3K inhibitor group, a naloxone injection (0.04 mL.kg-1) group and a naloxone injection (0.04 mL.kg-1) plus Xingnaojing Injection (3.6 mL.kg-1) group (n=8 per group). In addition, eight animals served as the sham group were performed same operation with the model group excepting no blockage of the blood vessels. After the operation, three different doses of Xingnaojing Injection and/or naloxone injection were given intravenously once a day for three days. Ten μL PI3K inhibitor (LY294002, 10 mmol/L) was injected via anterior cerebral ventricle at once after global brain ischemia. The awakening time after the first drug treatment, the grasping power and the autonomous activity within 10 min after the last drug treatment were recorded. The levels of both dopamine (DA) and glutamate (Glu) in cerebrospinal fluid were detected by ELISA. The pathological changes were observed in brain tissue slices with HE staining and the protein levels of Akt/p-Akt and cAMP-response element binding protein (CREB)/p-CREB in hippocampus were detected by Western blotting. Results: Comparing with the model group, single administration of Xingnaojing Injection could significantly shorten the waking time (P<0.05) and continuous administration of Xingnaojing Injection for 3 d could increase grasping power, distance, frequency and duration of autonomous activities (P<0.05 or P<0.01) in the deep coma rat. Also, Xingnaojing Injection could inhibit these increases in neurotransmitters DA and Glu contents (P<0.05 or P<0.01), and improve pathological changes of hippocampal tissue. Xingnaojing Injection significantly induced protein phosphorylation of both Akt and CREB (P<0.05 or P<0.01); this effect was inhibited by PI3K inhibitor (P<0.05 or P<0.01). Moreover, the protective effects of naloxone on awakening time, grasping power, the autonomous activity and hippocampus damage in global brain ischemia-induced deep coma could be enhanced by joint use of Xingnaojing Injection (P<0.05 or P<0.01). Conclusion: Xingnaojing Injection could significantly improve deep coma induced by global brain ischemia in rat, which is related to inducing PI3K/Akt-dependent protein phosphorylation of CREB, and reducing hippocampal damage. The protective effect of Xingnaojing Injection is synergistically enhanced by naloxone.

Standardized ileal digestible amino acid and metabolizable energy content of wheat from different origins and the effect of exogenous xylanase on their determination in broilers

This study was conducted to determine the standardized ileal digestible amino acids (SID AA) and nitrogen-corrected apparent metabolizable energy (AMEn) contents of 6 wheats from different origins in China and incidentally to investigate the effects of exogenous xylanase addition on SID AA and AMEn determination in broiler chicks. A total of 480 chicks were divided into 48 cages of 10 birds each balanced for body weight and fed 8 types of diets in a completely randomized design (6 replicated cages per diet) from 21 to 26 d of age. The individual wheat constituted the only source of crude protein in a semi-purified experimental diet. A nitrogen-free diet was designed to estimate basal endogenous AA loss and determine the SID AA. Titanium oxide (0.3%) was used as an indigestibility marker, and nutrient digestibility and retention were determined by the substitution method. From day 24 to 26, excreta samples were collected for AMEn determination. On day 26, the birds were euthanized, and ileum contents were obtained for AA digestibility determination. Wheat from Gansu had greater (P < 0.05) SID AA contents except Lys, Thr, Phe, and Cys, with a higher (P < 0.001) AMEn (11.83 MJ/kg) than the other wheats. The SID content of mean indispensable amino acids and dispensable amino acids were 87.35% and 88.17%, respectively, and the average AMEn value of 6 wheats was 11.14 MJ/kg. Compared with the diet without xylanase, the added xylanase resulted in higher (P < 0.05) SID contents of Met, Lys, Trp, Arg, Ile, Leu, Val, Gly, Asp, Glu, Pro, and Ala; the SID AA values were raised by 1.96% (mean of all AA); and the AMEn content was significantly increased (+0.87 MJ/kg) (P < 0.05). In conclusion, origins of wheats have significant effects on SID AA and AMEn values which were positively correlated with crude protein content of wheat; exogenous xylanase addition to a wheat-based poultry diet could significantly improve SID AA and AMEn contents for broilers.

Histological Distribution and Characterization of Collagen in European eel (Anguilla anguilla) Muscle

ABSTRACTThe histologic structure of eel muscle was observed, and the acid solubilized collagen (ASC) and pepsin solubilized collagen (PSC) from eel muscle were prepared and examined. The collagenous fiber amount in both head and tail seemed to be higher than that in the trunk. The Glu, Asp, Arg, Ala, Leu, and Lys contents accounted for about 54% of total amino acids in the eel muscle. There were no significant differences in the amino acid composition and ultraviolet spectra between ASC and PSC. The molecular weights of α1 subunit in both collagens were 129 and 123 kDa, respectively; but their molecular weights of α2 subunit were 113 kDa. According to peptide mapping analysis, it was found that there were obvious differences in primary structures between ASC and PSC. The amide A band positions of ASC and PSC appeared at 3320 cm−1 and 3312 cm−1 of Fourier transform infrared spectra, respectively. No obvious difference was found in the thermal stability of both collagens, probably due to the synergistic effect of molecular weight and hydrogen bonds.

ROLE OF AMINO ACIDS IN PROTECTING PECTINOPHORA GOSSYPIELLA (SAUND.) AGAINST STRONG PROTEIN-DENATURING ACTIVITY OF PHENOLIC COMPOUNDS IN COTTON PLANTS

To test if the generality of glycine secretion in the pink bollworm larvae related to the concentration of phenolic compounds (PCs), a feeding experiment with two concentrations of selected two PCs (pyrocatechol; Pyro & resorcinol; Res) was performed. Then, we determined and compared the lysine and glycine contents in the total body homogenate of treated and untreated 4th instar larvae. Results showed that the lysine and glycine contents recorded were 2.29 & 1.47 mg/100mg of control larval body weight. Lysine content increased at low PCs concentration by 5.68 & 7.42% for Pyro and Res, respectively. On the other hand, its concentration decreased at high PCs concentration by 0.87 & 0.44%, respectively. On the other hand, glycine content generally decreased (except at low concentration of Pyro; 8.84%) by 4.76, 4.08 & 12.24%. Also, it could be noted that the generality of glycine secretion related to the concentration of PCs; whereas the less in glycine content was more notable in high concentration of PCs. And, the loss in glycine content was more than that for lysine. Also, studies extend to other amino acids (AA) and the results indicated that it could be grouped AA in 3 groups: A high AA concentration (more than 3 mg/100mg): GLU and ASP acid. A moderate AA concentration (more than 2 mg/100mg): VAL, LEU, LYS, ARG, ALA and TYR. A low AA concentration (less than 2 mg/100mg): THR, ILE, PHE, HIS, CYS, SER, GLY and PRO. In the control PBW, glutamic acid and aspartic acid were present in high concentration (4.24 & 3.19 mg/100mg, respectively). As same manner with glycine; the losses in GLU and ASP contents were more than that for LYS. So, it could be used by PBW to overcome PCs toxicity. In addition, generally, at low PCs concentration, AA content increased except in the case of VAL and CYS. On contrast, at high PCs concentration, AA content decreased except in the case of MET, PHE, HIS and TYR. Commonly, it could be noted that Val, Cys, Gly and Ala had a higher percent of reduction. So, it means that other free amino acids may be used by some herbivores as counteractive agents against the denaturing activity of PCs.

The GABA shunt pathway in germinating seeds of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) under salt stress

AbstractSoil salinity is one of the major abiotic stresses affecting seed germination, crop growth and productivity. In this study, seeds of three wheat (Triticum aestiveum L.) and three barley (Hordeum vulgare L.) cultivars were treated with different concentrations of NaCl to investigate the effect of salt on seed germination physiology and metabolism through the characterization of seed germination pattern, gamma-aminobutyric acid (GABA) shunt metabolite accumulation [GABA, glutamate (Glu) and alanine (Ala)] and glutamate decarboxylase (GAD) expression using RT-PCR. A trend of decreasing germination percentage with increasing NaCl concentrations was observed. Under all salt stress treatments, data showed significant increase with positive correlation (r = 0.50–0.99) between abundance of GABA shunt metabolites and salt concentration in all wheat and barley cultivars for 5 days. Increased GABA content was associated with a small but significant increase in Ala and Glu content in all cultivars. In all NaCl treatments, the transcription of GAD in terms of RNA abundance showed a significant increase in all cultivars with positive correlation (r = 0.50–0.98). Data showed significant association between GAD RNA transcription and the response of germinating seeds to salt stress in terms of GABA shunt metabolite accumulation. The elevated expression of GAD under salinity suggests the need for elevated activity of the GAD-mediated conversion of Glu to GABA during seed germination, which provides alternative metabolic routes to the respiratory machinery, balancing carbon and nitrogen metabolism and osmolyte synthesis in germinating seeds of wheat and barley under salt stress.