Changes In Amino Acid Concentrations Research Articles

Green synthesis of Bio-CuS quantum dots by sulfate reducing bacteria for solid-phase photocatalytic degradation of polyethylene film

In this study, CuS quantum dots (QDs) synthesized through biological method were used as photocatalysts for the photocatalytic degradation of polyethylene (PE) plastics. Bio-CuS QDs were synthesized through a green process using sulfate reducing bacteria, while Che-CuS QDs were prepared by chemical precipitation for comparison. The crystal structure, surface morphology, microstructure and optical properties of the samples were detected by XRD, SEM, TEM and UV–Vis DRS. The green synthesis mechanism of Bio-CuS was inferred by analyzing changes in amino acid concentration and the three-dimensional fluorescence spectra of extracellular polymeric substances before and after synthesis. The photocatalytic degradation of PE films by Che-CuS and Bio-CuS was investigated. The weight loss rates of PE+Che-CuS and PE+Bio-CuS were 9.1 % and 12.8 % after 14 d irradiation, respectively, while pure PE was only 1.7 %. Furthermore, SEM, UV–Vis DRS, contact angle, TGA, GPC and FTIR were adopted to characterize the PE film. The results revealed that PE+Che-CuS and PE+Bio-CuS underwent major changes in morphology, transparency, hydrophilicity, thermal stability, molecular weight and functional groups compared with PE, with more pronounced changes observed for PE+Bio-CuS. The quenching experiments of active species showed that h+ and·OH were critical to the PE degradation. The intermediate products of PE degradation were analyzed by GC–MS, and a possible degradation pathway was proposed. In addition, the possible mechanism of photocatalytic degradation of PE films by CuS QDs was proposed. This work provides a green remediation approach to addressing the growing plastic pollution in the environment.

Use of supercritical CO2 to improve the quality of lupin protein isolate

Lupins are an excellent source of protein which can be used to obtain protein isolates with potential use in the food industry. Some studies use supercritical CO2 (SC-CO2) to defat legume flours, but no study analyzes the effect of applying this technology directly to the protein isolate. This article has proposed the use of SC-CO2 to improve lupin protein isolate (LPI) quality. SC-CO2 increased the LPI purity while reducing oil and other antitechnological factors (saponins and polyphenols). The treatment significantly improved the LPI color due to the elimination of the lipid fraction and lipophilic pigments (carotenoids). No changes in amino acid contents or chemical score were observed due to the SC-CO2. Finally, the treatment improved or did not affect the main LPI technofunctional properties. Therefore, SC-CO2 is a promising technique to enhance the quality of protein isolates, without affecting or improving their functional properties.

The contribution of Ca and Mg to the accumulation of amino acids in maize: from the response of physiological and biochemical processes

BackgroundThe quality of maize kernels is significantly enhanced by amino acids, which are the fundamental building blocks of proteins. Meanwhile, calcium (Ca) and magnesium (Mg), as important nutrients for maize growth, are vital in regulating the metabolic pathways and enzyme activities of amino acid synthesis. Therefore, our study analyzed the response process and changes of amino acid content, endogenous hormone content, and antioxidant enzyme activity in kernels to the coupling addition of sugar alcohol-chelated Ca and Mg fertilizers with spraying on maize.Result(1) The coupled addition of Ca and Mg fertilizers increased the Ca and Mg content, endogenous hormone components (indole-3-acetic acid, IAA; gibberellin, GA; zeatin riboside, ZR) content, antioxidant enzyme activity, and amino acid content of maize kernels. The content of Ca and Mg in kernels increased with the increasing levels of Ca and Mg fertilizers within a certain range from the filling to the wax ripening stage, and significantly positively correlated with antioxidant enzyme activities. (2) The contents of IAA, GA, and ZR continued to rise, and the activities of superoxide dismutase (SOD) and catalase (CAT) were elevated, which effectively enhanced the ability of cells to resist oxidative damage, promoted cell elongation and division, and facilitated the growth and development of maize. However, the malondialdehyde (MDA) content increased consistently, which would attack the defense system of the cell membrane plasma to some extent. (3) Leucine (LEU) exhibited the highest percentage of essential amino acid components and a gradual decline from the filling to the wax ripening stage, with the most substantial beneficial effect on essential amino acids. (4) CAT and SOD favorably governed essential amino acids, while IAA and MDA negatively regulated them. The dominant physiological driving pathway for the synthesis of essential amino acids was “IAA-CAT-LEU”, in which IAA first negatively drove CAT activity, and CAT then advantageously controlled LEU synthesis.ConclusionThese findings provide a potential approach to the physiological and biochemical metabolism of amino acid synthesis, and the nutritional quality enhancement of maize kernel.

Pharmacodynamic and targeted amino acid metabolomics researches on the improvement of diabetic retinopathy with Fufang Xueshuantong component compatibility

The Fufang Xueshuantong capsule (FXT) has significant preventive and therapeutic effects on diabetic retinopathy(DR), but the compatibility of its active components remains to be thoroughly explored. In this study, a zebrafish diabetic retinopathy model was established using high-mixed sugars, and the optimal ratios of notoginseng total saponins, total salvianolic acid, astragaloside, and harpagide were selected through orthogonal experiments. Furthermore, we used UPLC-QqQ/MS to detect the changes in amino acid content of DR zebrafish tissues after administration of FXT and its compatible formula to analyze the effects of FXT and its compatible formula on amino acid metabolites. The results showed that the final compatibility ratios of the components were 8: 5: 1: 6.6 by comprehensive evaluation of the indicators. FXT and its compatibility formula had beneficial effects on retinal vasodilatation, lipid accumulation in the liver, total glucose, and VEGF levels in DR zebrafish, and all of them could call back some amino acid levels in DR zebrafish. In this research, we determined the compatible formulation of the active ingredients in the FXT and investigated their efficacy in DR zebrafish for further clinical applications.

Cardiac Metabolic Stress During Ischemia and Reperfusion in Patients Undergoing Coronary Artery Bypass Surgery Using Either Calafiore or Modified Del Nido Cardioplegic Solutions

Objective: Calafiore and modified del Nido cardioplegic solutions are currently being used during coronary artery bypass surgery. This study aims to compare myocardial ischemic stress associated with both solutions by studying the changes in cardiac metabolites during cardioplegic ischemic arrest and early reperfusion.Methods: Biopsy specimens were taken from the left ventricles of 20 patients undergoing routine coronary artery bypass grafting using Calafiore or modified del Nido cardioplegic solutions. Biopsies were taken immediately after the beginning of extracorporeal circulation (basal biopsy), 30 min after application of the aortic cross‐clamp (ischemic biopsy), and 20 min following the removal of aortic cross‐clamp (reperfusion biopsy) and were analyzed for their amino acid and lactic acid contents using amino acid analyzer and appropriate kits. Peripheral blood samples were also collected for the determination of blood concentrations of cardiac proteins (CK‐MB and troponin I) using an immunofluorescence scanner.Results: Both CK‐MB and troponin I increased significantly 12 h postoperatively and were associated with an increase in myocardial lactic acid, but there were no significant differences in markers of myocardial injury between the two groups. Comparison of amino acid concentrations between the two groups according to sampling time showed that glutamic acid concentrations were significantly lower in the Calafiore cardioplegia group compared to the del Nido cardioplegia group, but there were no other significant differences in markers of metabolic stress (taurine and alanine/glutamate ratio) between the two groups. Moreover, there were no significant differences in changes in amino acid concentrations regardless of the type of cardioplegic solution used.Conclusions: Cardioplegic ischemic arrest and early reperfusion are associated with a rise in myocardial metabolic stress. Both Calafiore and modified del Nido cardioplegic solutions are effective in attenuating myocardial substrate derangements and confer equal myocardial protection during routine coronary artery bypass surgery.Trial Registration: ClinicalTrials.gov identifier: NCT06287372

Comparative study on chemical components of Gannan navel orange in different maturity stages based on UPLC-QTOF-MS metabolomics

Metabolites changes during fruit growth are currently being studied intensively. In this experiment, Ultra-high performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry was used to identify metabolites during the growing phase of navel oranges. A total of 63 metabolites were identified, and monitored changes in amino acid content. Principal component analysis and Partial least-squares-discriminate analysis were used to construct a cluster analysis model among navel orange metabolites. Among the 19 differential metabolites, flavonoids were the main metabolic markers during the growth of navel oranges. Correlation cluster analysis was used to fit the correlation between the characteristic components, and it was found that many flavonoids were highly correlated. Finally, combined with Kyoto Encyclopedia of Genes and Genomes enrichment analysis, the key metabolic pathway was identified as flavonoid synthesis. The α-glucosidase inhibition experiment showed that with the growth of navel orange, the inhibition rate of the metabolites to α-glucosidase activity decreased continuously. This study provides a necessary basis for exploring the metabolic mechanism of navel orange growth.

P06-020-23 Changes in Amino Acid Content During Heat Treatment of Sardines and Sprats

P06-020-23 Changes in Amino Acid Content During Heat Treatment of Sardines and Sprats

The metabolic differences of anestrus, heat, pregnancy, pseudopregnancy, and lactation in 800 female dogs.

Reproduction causes major hormonal and physiological changes to the female body. However, the metabolic changes occurring during canine reproduction are scarcely studied. In this cross-sectional study, we assessed the metabolic effects of canine reproductive status using a 1H NMR metabolomics platform optimized and validated for canine use. The study population consisted of a total of 837 healthy, intact female dogs in breeding age, of which 663 dogs were in anestrus, 78 in heat, 43 were pseudopregnant, 15 were pregnant, and 38 were lactating. The differences in metabolite profiles between these states were studied by the Kruskal-Wallis test with post-hoc tests performed using the Dunn's test, and visualized by box plots and a heatmap. The ability of the metabolite profile to differentiate pregnant dogs from non-pregnant ones was assessed by creating a multivariate Firth logistic regression model using forward stepwise selection. Lactation, pregnancy and heat all were associated with distinct metabolic changes; pregnancy caused major changes in the concentrations of glycoprotein acetyls, albumin and creatinine, and smaller changes in several lipids, citrate, glutamine, and alanine. Pseudopregnancy, on the other hand, metabolically largely resembled anestrus. Lactation caused major changes in amino acid concentrations and smaller changes in several lipids, albumin, citrate, creatinine, and glycoprotein acetyls. Heat, referring to proestrus and estrus, affected cholesterol and LDL metabolism, and increased HDL particle size. Albumin and glycoprotein acetyls were the metabolites included in the final multivariate model for pregnancy detection, and could differentiate pregnant dogs from non-pregnant ones with excellent sensitivity and specificity. These results increase our understanding of the metabolic consequences of canine reproduction, with the possibility of improving maternal health and ensuring reproductive success. The identified metabolites could be used for confirming canine pregnancy.

Plasma Amino Acid Concentrations in Children With Severe Malaria Are Associated With Mortality and Worse Long-term Kidney and Cognitive Outcomes.

Global changes in amino acid levels have been described in severe malaria (SM), but the relationship between amino acids and long-term outcomes in SM has not been evaluated. We measured enrollment plasma concentrations of 20 amino acids using high-performance liquid chromatography in 500 Ugandan children aged 18 months to 12 years, including 122 community children and 378 children with SM. The Kidney Disease: Improving Global Outcomes criteria were used to define acute kidney injury (AKI) at enrollment and chronic kidney disease (CKD) at 1-year follow-up. Cognition was assessed over 2 years of follow-up. Compared to laboratory-defined, age-specific reference ranges, there were deficiencies in sulfur-containing amino acids (methionine, cysteine) in both community children and children with SM. Among children with SM, global changes in amino acid concentrations were observed in the context of metabolic complications including acidosis and AKI. Increases in threonine, leucine, and valine were associated with in-hospital mortality, while increases in methionine, tyrosine, lysine, and phenylalanine were associated with postdischarge mortality and CKD. Increases in glycine and asparagine were associated with worse attention in children <5 years of age. Among children with SM, unique amino acid profiles are associated with mortality, CKD, and worse attention.

Changes in the enzymes, amino acids, metal ions and flavor profile during fermentation of African locust bean seeds ‘Parkia biglobosa’ to Daddawa

Daddawa/iru, a product of African locust bean (Parkia biglobosa) seeds, is widely used as food condiment by many tribes in West Africa. This study aimed to determine some of the changes which occur during the microbial fermentation of African locust bean seed. The daily changes in pH, amylase, lipase and protease secretion were monitored. Changes in amino acid concentration, mineral ion composition were also monitored; the presence of hydrocarbons and volatile flavor compounds were also determined. The pH increased throughout fermentation and was above 8.5 by 96 h fermentation. Enzyme production was highest after 48 h fermentation. The highest increase in amino acid concentration was observed after 72 h fermentation. The essential amino acids which increased after 72 h fermentation include arginine (48.8%), threonine (25.2%), valine (24.8%), and methionine (20.0%), histidine (10.3%), isoleucine (19.2%), leucine (15.9%), lysine (15.24%), phenylalanine (14.9%), and tryptophan (12.5%). A higher metal ion concentration was observed before fermentation (0 h) than during or after fermentation of the locust bean seeds. Various hydrocarbons, fatty acids, esters and alcohols were observed at different stages of the fermentation.&#x0D;

Association between mitochondrial DNA haplogroups J and K, serum branched-chain amino acids and lowered capability for endurance exercise

BackgroundEndurance exercise training promotes the catabolism of branched-chain amino acids (BCAAs) in skeletal muscles. We have previously shown that mitochondrial DNA (mtDNA) haplogroups J and K are markers of low responders in endurance training. In this paper, we hypothesize that BCAA catabolism is a surrogate marker of lower respiratory chain activity attributed to these haplogroups. We evaluated whether exercise-induced changes in amino acid concentrations differ between subjects harbouring mtDNA haplogroups J or K and those with non-JK haplogroups.MethodsFinnish male conscripts (N = 633) undertook the 12-min Cooper running test at the beginning and end of their military service. The intervention during the service mainly included endurance aerobic exercise and sports-related muscle training. Concentrations of seven amino acids were analysed in the serum using a high-throughput 1H NMR metabolomics platform. Total DNA was extracted from whole blood, and restriction fragment analysis was used to determine mtDNA haplogroups J and K.ResultsThe concentrations of the seven amino acids were higher following the intervention, with the exception of phenylalanine; interestingly, the increase in the concentrations of three BCAAs was larger in subjects with haplogroup J or K than in subjects with non-JK haplogroups (p = 0.029). MtDNA haplogroups J and K share two common nonsynonymous variants. Structural analysis based on crystallographic data on bovine complexes I and III revealed that the Leu18 variant in cytochrome b encoded by m.14798T > C may interfere with ubiquinone binding at the Qi site in complex III.ConclusionsThe increase in the concentrations of serum BCAAs following exercise intervention differs between subjects harbouring mtDNA haplogroup J or K and those harbouring non-JK haplogroups. Lower response in endurance training and difference in exercise-induced increase in the concentrations of serum BCAAs suggest decreased respiratory chain activity. Haplogroups J and K share m.14798T > C in MT-CYB, which may hamper the function of complex III.

Histopathological evidence that diethylene glycol produces kidney and nervous system damage in rats

Diethylene glycol (DEG) is an organic compound that has been found as an adulterant in consumer products as a counterfeit glycerin. Diethylene glycol is metabolized to two primary metabolites: 2-hydroxyethoxyacetic acid (2-HEAA) and diglycolic acid (DGA), the latter shown to accumulate in the kidney and cause dose-dependent cell necrosis. DEG poisonings are characterized predominately by acute kidney injury (AKI) but have also produced delayed neurological sequelae such as sensorimotor neuropathy. To better understand these effects, Wistar-Han rats were orally administered a water control or doses of 4 g/kg-6 g/kg DEG every 12 or 24 h for 7 days, with kidney, brain, and spinal cord tissue collected for histopathological analysis. This dosing paradigm resulted in approximately 25 % of the DEG-treated animals developing AKI and also neurotoxicity (sensorimotor dysfunction and elevated cerebrospinal fluid (CSF) protein). Kidney pathology included a severe, diffuse acute kidney tubular necrosis predominantly affecting proximal convoluted tubules. Scattered birefringent crystals consistent with calcium oxalate monohydrate were also found in the proximal tubule of animals with AKI. Demyelination in the dorsal and lateral white matter regions of the cervical, thoracic, and lumbar areas of the spinal cord of a DEG-treated animal with AKI was documented, establishing the neuropathology in DEG-treated animals that developed neurotoxicity. There were significant changes in amino acid concentrations in the CSF that may reflect the neurotoxicity of DEG, specifically glutamate and glutamine, but with no ammonia change. These studies characterized the pathologic aspects of the neurotoxicity in a DEG repeat-dose model.

Relationship between protein structure and eating quality of rice under different nitrogen application rate

AbstractBackground and ObjectivesThe mechanisms underlying the effects of proteins on the eating quality of rice remain elusive. In this study, the effect of content and secondary structure of four rice proteins (glutelin, globulin, albumin, and prolamin) on eating quality was investigated with rice subjected to nitrogen treatment at 160, 210, 260, 315, and 420 kg N/ha in the field.FindingsThe results showed that applying nitrogen fertilizer remarkably increased glutelin and globulin contents (p &lt; .05), especially the methionine content of globulin, leading to increased hardness of cooked rice. Moreover, excessive nitrogen significantly reduced the ratio of the prolamin α‐helix structure (p &lt; .05), which had a significant correlation with hardness and pasting temperature (p &lt; .05), at correlation coefficients of −0.859 and 0.828, respectively.ConclusionBesides protein content, the changes in amino acid content and protein secondary structure were also closely related to the eating quality of rice.Significance and NoveltyThose results provided a new idea for breeding, cultivating, and processing technology regulation aimed at improving the eating quality of rice.

Disorder of intestinal amino acid pathway in depression-like offspring rats induced by maternal separation.

To investigate the intestinal amino acids pathway in depression-like offspring rats induced by maternal separation. Sprague-Dawley (SD) female rats were randomly divided into a control group (=8) and a maternal separation group (=8). After normal delivery, the maternal rats were separated from offsprings for 14 consecutive days and 3 h per day in maternal separation group; while rats in the control group was received no interventions in postpartum. Depression-like behaviors of offspring rats were evaluated using the sucrose preference test, novelty suppressed feeding test, and forced swimming test. Amino acid analyzer was used to detect the changes of amino acid contents in the small intestine, and the expressions of alanine-serine-cysteine transporter 2 (ASCT2), solute carrier superfamily 6 member 19 (BAT1) and L-type amino acid transporter 1(LAT1) were detected by Western blot. The weight of the offspring rats in the maternal separation group was significantly lower than that of the control group at 21 and 28 d (=4.925 and 5.766, all <0.01). Compared with the control group, the percentage of sucrose preference of the offspring rats in the maternal separation group was significantly reduced (=2.709, <0.05), and the feeding latency was significantly prolonged (=-13.431, <0.01). The immobility time in FST of maternal separation group was significantly longer (=-3.616, <0.01).Increased concentration of aspartic acid (=-6.672, <0.01) and down-regulation of glutamine (=3.107, <0.01) and glycine (=9.781, <0.01) were observed in maternal separation group. Western blot analysis revealed that the protein expressions of ASCT2 (=6.734, <0.01) and BAT1 (=9.015, <0.01) in maternal separation group were reduced, while the expression of LAT1 was increased (=-8.942, <0.01). Maternal separation can induce the depression-like behavior in offspring rats; the amino acid contents and the amino acid transporter expression in the small intestine are reduced, which may be related to depression-like behavior induced by maternal separation.

Sarcopenic Obesity and Amino Acids: Concord Health and Ageing in Men Project.

Although characteristic changes in amino acid concentrations occur in obesity and sarcopenia, amino acids concentrations have not been reported in sarcopenic obesity. We studied n = 831 men aged 75 years and older from the 5-year follow-up of the Concord Health and Ageing in Men Project. Sarcopenia was defined using the Foundation of the National Institutes of Health criteria and obesity was defined as >30% fat mass. There were 31 men (3.7%) who had sarcopenic obesity. Branched chain amino acids were elevated in the obese (but not sarcopenic) group (n = 348) but reduced in both the sarcopenic (but not obese) (n = 44) and the sarcopenic obese groups. Apart from this, most of the amino acid concentrations were between those for the obese and the sarcopenic groups. Yet despite low concentrations of branched chain amino acids, the sarcopenic obese group had indications of insulin resistance and diabetes mellitus (fasting glucose and insulin concentrations, homeostatic model assessment, and percentage of participants taking diabetes medications) that were similar to the obese group. In summary, sarcopenic obese participants did not have a unique amino acid signature. In obesity, elevated branched chain amino acids are not a prerequisite for insulin resistance and diabetes if obesity is associated with sarcopenia.

Weight loss through lifestyle modification or liraglutide is associated with improvement of NAFLD severity and changes in amino acid concentrations

Weight loss through lifestyle modification or liraglutide is associated with improvement of NAFLD severity and changes in amino acid concentrations

Analysis of melatonin regulation of germination and antioxidant metabolism in different wheat cultivars under polyethylene glycol stress

Melatonin is effective in enhancing various abiotic stress resistances of plants. However, its underlying mechanisms in drought-resistance in winter wheat (Triticum aestivum L.) is not clear. The goal of this work was to investigate the effect of melatonin on seed germination and to evaluate leaf antioxidant physiology for two wheat varieties. Experiments included 20% PEG, melatonin plus 20% PEG and a control using two contrasting wheat varieties (JM22– drought sensitive and HG35– drought resistant). Melatonin levels were 0, 1, 10, 100 and 300 μmol L-1. Results revealed that 300 μmol L-1 of melatonin alleviated the negative effect of water stress on germination and increased radicle length, radicle number, and plumule length of the germinated seeds. Principal component analysis showed a significant change in amino acid content during germination and this change was dependent on melatonin concentration and the variety. Lysine (Lys) content in wheat seeds under the PEG plus 300 μmol L-1 melatonin treatment increased compared with that of the seeds under PEG alone. There was a significant and positive correlation between Lys content and morphological index of germination. During seedling growth, soluble protein was involved in osmotic adjustment and superoxide dismutase (SOD) activity was increased to mitigate the damage in the cytomembrane of JM 22 leaf under 300 μmol L-1 melatonin plus PEG treatment. The effect of melatonin was dependent on SOD activity increasing significantly for HG35—a drought resistant variety. The results of this work lays a foundation for further studies to determine if melatonin can be economically used to mitigate the impact of dry planting conditions on wheat productivity in North China Plain.

Serum Metabolome Changes in Relation to Prothrombotic State Induced by Combined Oral Contraceptives with Drospirenone and Ethinylestradiol

The association between hypercoagulability and use of drospirenone (DRSP) and ethinylestradiol (EE) containing combined oral contraceptives (COCs) is an important clinical concern. We have previously reported that the two formulations of DRSP combined with EE (namely, DRSP/20EE and DRSP/30EE) bring about a prothrombotic state in hemostatic traits of female users. We report here the serum metabolomic changes in the same study cohort in relation to the attendant prothrombotic state induced by COC use, thus offering new insights on the underlying biochemical mechanisms contributing to the altered coagulatory profile with COC use. A total of 78 healthy women participated in this study and were grouped as follows: control group not using oral contraceptives (n = 25), DRSP/20EE group (n = 27), and DRSP/30EE group (n = 26). Untargeted metabolomics revealed changes in amino acid concentrations, particularly a decrease in glycine and an increase in both cysteine and lanthionine in the serum, accompanied by variations in oxidative stress markers in the COC users compared with the controls. Of importance, this study is the first to link specific amino acid variations, serum metabolites, and the oxidative metabolic profile with DRSP/EE use. These molecular changes could be linked to specific biophysical coagulatory alterations observed in the same individuals. These new findings lend evidence on the metabolomic substrates of the prothrombotic state associated with COC use in women and informs future personalized/precision medicine research. Moreover, we underscore the importance of an interdisciplinary approach to evaluate venous thrombotic risk associated with COC use.

Adaptive responses to maternal nutrient restriction alter placental transport in ewes

IntroductionMaternal nutrient partitioning, uteroplacental blood flow, transporter activity, and fetoplacental metabolism mediate nutrient delivery to the fetus. Inadequate availability or delivery of nutrients results in intrauterine growth restriction (IUGR), a leading cause of neonatal morbidity and mortality. Maternal nutrient restriction can result in IUGR, but only in an unforeseeable subset of individuals. MethodsTo elucidate potential mechanisms regulating fetal nutrient availability, singleton sheep pregnancies were generated by embryo transfer. Pregnant ewes received either a 50% NRC (NR; n = 24) or 100% NRC (n = 7) diet from gestational Day 35 until necropsy on Day 125. Maternal weight did not correlate with fetal weight; therefore, the six heaviest (NR Non-IUGR) and five lightest (NR IUGR) fetuses from nutrient-restricted ewes, and seven 100% NRC fetuses, were compared to investigate differences in nutrient availability. ResultsInsulin, multiple amino acids, and their metabolites, were reduced in fetal circulation of NR IUGR compared to NR Non-IUGR and 100% NRC pregnancies. In contrast, glucose in fetal fluids was not different between groups. There was a nearly two-fold reduction in placentome volume and fetal/maternal interface length in NR IUGR compared to NR Non-IUGR and 100% NRC pregnancies. Changes in amino acid concentrations were associated with altered expression of cationic (SLC7A2, SLC7A6, and SLC7A7) and large neutral (SLC38A2) amino acid transporters in placentomes. DiscussionResults establish a novel approach to study placental adaptation to maternal undernutrition in sheep and support the hypothesis that amino acids and polyamines are critical mediators of placental and fetal growth in sheep.

The ideal protein profile for late-finishing pigs in precision feeding systems: Threonine

Optimal amino acid ratios for pigs have been established for conventional phase feeding systems, but these ratios may differ for precision feeding systems. Our objective was to assess the impact of different dietary Thr inclusion levels (70, 85, 100, 115, or 130% of the estimated ideal 0.65 Thr:Lys ratio) on growth performance, plasma biochemical parameters, and splanchnic and muscle AA composition in pigs raised in a conventional group phase feeding (GPF) system and in an individual precision feeding (IPF) system. A total of 110 finishing pigs (110 ± 7.02 kg initial body weight; 11 pigs per treatment) were housed in the same room for 21 d. Pigs were randomly assigned to a 2 × 5 factorial arrangement and fed using automatic feeders. Individual pigs were considered the experimental units. Five pigs per treatment were slaughtered at the end of the trial. The gain:feed ratio was not affected by feeding system, but there was a quadratic effect of Thr inclusion rate (P < 0.05). Lysine intake was 16% greater and Thr intake was 15% greater for the GPF pigs than for the IPF pigs (P < 0.05). Protein deposition (g/d) was not affected by any treatment. Protein deposition in daily gain was affected by the interaction between Thr inclusion rate and feeding system, with a quadratic (P < 0.05) effect for the GPF pigs and a cubic (P < 0.10) effect for the IPF pigs. The pigs in IPF consumed 14% less (P < 0.05) crude protein and excreted 17% less (P < 0.05) N than the GPF pigs did. The pigs in IPF retained 9% more (P < 0.05) N than the GPF pigs. Plasma urea values were 9% higher (P < 0.05) in GPF than those in IPF. The gamma-glutamyl transferase enzyme decreased (P < 0.05) in a quadratic manner within IPF but increased (P < 0.05) in a quadratic manner within GPF. In the IPF systems, the average concentration of albumin and C-reactive protein tended (P < 0.10) to be 2 and 22% lower, respectively, than in GPF. Changes in amino acid concentrations occurred mainly in the liver of the IPF pigs. The pigs in IPF had higher (P < 0.05) concentrations of collagen in the longissimus dorsi than the pigs in GPF. Lastly, IPF allowed standardized ileal digestible Lys and Thr intakes to decrease by 16 and 15%, respectively, without differences in average daily gain and gain:feed ratio in comparison with GPF.