Plasma Amino Acid Concentrations Research Articles

Comparison of plasma amino acid concentrations after whey protein hydrolysate intake in young men at rest and post-resistance exercise

Comparison of plasma amino acid concentrations after whey protein hydrolysate intake in young men at rest and post-resistance exercise

Differences in daily milk production during early pregnancy alter placental characteristics and neonatal metabolic amino acid levels in dairy cows.

We investigated the effects of differences in milk production during early pregnancy on placental characteristics at full term, calf birth weights, and their metabolic status. Thirty-four Holstein cows were categorized into three groups (Low, n = 9; Middle, n = 16; High, n = 9) based on the quartile of average daily 4% fat-corrected milk production during early pregnancy. The High group showed higher milk component production than the other groups (P < 0.05) during early and mid-pregnancy. Although most placental characteristics did not differ significantly among the groups, cows in the High group had larger individual cotyledons and fewer medium-sized cotyledons than those in the Low group (P < 0.05). Plasma amino acid concentrations of calves in the Low and High groups were significantly higher than those of calves in the Middle group, although calf birth weights were similar among the groups. Furthermore, cows in the Low group had longer dry periods than those in the High (P = 0.004) and Middle (P = 0.058) groups. This suggests that cows in the Low group may have provided more amino acids to the fetus because of low lactation and long dry periods. Conversely, cows in the High group required more energy for lactation during early pregnancy, which can reduce nutrient availability to the placenta and fetus; however, increasing individual cotyledonary sizes during late pregnancy may ensure that the same amounts of amino acids as those in cows in the Low group are supplied to the fetus, recovering the birth weights.

Subchronic tolerance trials of graded oral supplementation with ornithine hydrochloride or citrulline in healthy adults

Ornithine and citrulline are amino acids used in dietary supplements and nutritional products consumed by healthy consumers, but the safe supplementation levels of these compounds are unknown. The objective of this study was to conduct two 4-week clinical trials to evaluate the safety and tolerability of graded dosages of oral ornithine (as hydrochloride) and citrulline. Healthy male adults (n = 60, age 41.4 ± 1.5 years) completed graded dosages of either ornithine hydrochloride (3.2, 6, 9.2, and 12 g/day) or citrulline (6, 12, 18, and 24 g/day) supplement for 4 weeks with 2-week wash-out periods in between. Primary outcomes included vitals, a broad spectrum of circulating biochemical analytes, body weight, sleep quality, and mental self-assessment. In the ornithine hydrochloride supplementation group, minor increase in plasma aspartic acid and glutamic acid concentrations was observed at the highest intake dosages. In the citrulline supplementation group, minor changes in laboratory data for serum lactate dehydrogenase and plasma amino acid concentration of lysine, methionine, threonine, aspartic acid, glutamic acid, glutamine and ornithine, arginine, and citrulline itself were measured. No other changes in measured parameters were observed, and study subjects tolerated 4-week-long oral supplementation of ornithine hydrochloride or citrulline without treatment-related adverse events. A clinical, no-observed-adverse-effect-level (NOAEL) of ornithine hydrochloride and citrulline supplementation in healthy adult males was determined to be 12 g/day and 24 g/day (4 weeks), respectively.

Elevated circulating level of β-aminoisobutyric acid (BAIBA) in heart failure patients with type 2 diabetes receiving sodium-glucose cotransporter 2 inhibitors

AimsThe mechanism by which a sodium-glucose cotransporter inhibitor (SGLT2i) induces favorable effects on diabetes and cardiovascular diseases including heart failure (HF) remains poorly understood. Metabolomics including amino acid profiling enables detection of alterations in whole body metabolism. The aim of this study was to determine whether plasma amino acid profiles are modulated by SGLT2i use in HF patients with type 2 diabetes mellitus (T2DM).MethodsWe retrospectively examined 81 HF patients with T2DM (68 ± 11 years old; 78% male). Plasma amino acid concentrations in a fasting state after stabilization of HF were determined using ultraperformance liquid chromatography. To minimize potential selection bias in the retrospective analyses, the differences in baseline characteristics between patients receiving an SGLT2i and patients not receiving an SGLT2i were controlled by using an inverse probability of treatment weighting (IPTW)-adjusted analysis.ResultsOf amino acids measurable in the present assay, plasma β-aminoisobutyric acid (BAIBA), an exercise-induced myokine-like molecule also known as 3-aminoisobutyric acid or 3-amino-2-methyproponic acid, was detected in 77% of all patients and the proportion of patients in whom plasma BAIBA was detected was significantly higher in patients receiving an SGLT2i than in patients not receiving an SGLT2i (93% vs. 67%, p = 0.01). Analyses in patients in whom plasma BAIBA was detected showed that plasma BAIBA concentration was significantly higher in patients receiving an SGLT2i than in patients not receiving an SGLT2i (6.76 ± 4.72 vs. 4.56 ± 2.93 nmol/ml, p = 0.03). In multivariate logistic regression analyses that were adjusted for age and sex, SGLT2i use was independently associated with BAIBA detection. The independent association between BAIBA and SGLT2i use remained after inclusion of body mass index, HF with reduced ejection fraction, ischemic etiology, renal function, NT-proBNP, albumin, hemoglobin, and HbA1c into the Cox proportional hazards model. When the differences in baseline characteristics between patients receiving an SGLT2i and patients not receiving an SGLT2i were controlled by using an IPTW-adjusted analysis, least squares mean of plasma BAIBA concentration was significantly higher in patients receiving an SGLT2i than in patients not receiving an SGLT2i.ConclusionSGLT2i use is closely associated with increased circulating BAIBA concentration in HF patients with T2DM.

Plasma Amino Acid Concentration in Obese Horses with/without Insulin Dysregulation and Laminitis.

Laminitic horses commonly suffer from an endocrine disease such as equine metabolic syndrome. Hyperinsulinemia is considered a key factor in the pathogenesis of laminitis. Since insulin also affects protein turnover in the body, the resting plasma amino acid concentrations of obese horses that were presented for a combined glucose insulin test (CGIT) were determined. In total, 25 obese horses and two lean horses with recurrent laminitis underwent a CGIT. Of these, five were not insulin dysregulated (obese), 14 were insulin dysregulated (ID), and eight were insulin-dysregulated and laminitic (IDL). Significant differences in the resting concentrations between obese and insulin dysregulated and laminitic (citrulline p = 0.038, obese: 73.001 ± 12.661 nmol/mL, IDL: 49.194 ± 15.486 nmol/mL; GABA p = 0.02, obese: 28.234 ± 3.885 nmol/mL, IDL: 16.697 ± 1.679 nmol/mL; methionine p = 0.018, obese: 28.691 ± 5.913 nmol/mL, IDL: 20.143 ± 3.09 nmol/mL) as well as between insulin dysregulated individuals with and without laminitis (GABA p &lt; 0.001, ID: 28.169 ± 6.739 nmol/mL) regarding three amino acids were determined. This may be an interesting approach, especially for diagnostic testing and possibly also for the feed supplements of horses at risk of developing laminitis. However, further research, including a higher number of cases, is required.

The effect of an intervention of porcine protein versus maltodextrin supplement on CONvalescence of FUnCtional outcomes after IcU Stay (CONFUCIUS): Study protocol for a randomized controlled, single-center, double-blind trial.

Patients discharged from the Intensive Care Unit (ICU) frequently suffer from ICU-acquired weakness because of immobilization and massive inflammation-induced muscle mass loss. Consequently, rehospitalization, reduced quality of life (QoL), increased disabilities, and higher post-ICU mortality is observed. Exercise rehabilitation and optimal nutrition, particularly protein intake, are pivotal to regaining muscle mass and function. Studies have shown that protein requirements in the post-ICU phase are often unmet. Furthermore, protein supplementation in other patient groups has shown beneficial effects. However, a study on protein supplementation during the post-ICU period is lacking. This study aims to investigate the effect of a six-week intervention of daily porcine protein supplementation versus an isocaloric control (maltodextrin) on functional outcomes in the post-ICU period in patients with moderately severe ICU-acquired weakness. 72 post-ICU patients with moderately severe ICU-acquired weakness of Hospital Gelderse Vallei will be randomly assigned to either the intervention or the control group (36 per arm). The intervention group receives a porcine protein supplement twice a day. The control group receives a maltodextrin supplement twice a day. The intervention starts on the first day in the general ward and lasts 42 days (6 weeks). The primary outcome is the between-group difference in physical function at hospital discharge (t;=2), the end of the intervention (t;=3, day 42), and the 3-month follow-up (t;=4) expressed as a composite score consisting of handgrip strength, muscle strength leg, muscle strength arm and exercise capacity. Secondary outcomes encompass physical function, QoL, Activity of daily living (ADL), and plasma amino acids concentrations. Lastly, ICU readmission after ICU discharge, hospital readmission after hospital discharge, and overall survival status will be considered. Linear mixed models will be used to test the treatment effect for the primary and secondary outcome measures. This trial will be the first to investigate porcine protein supplementation compared with carbohydrate supplementation in the post-ICU period aiming to improve functional outcomes of ICU survivors with moderately severe ICU-acquired weakness. The study has been registered at ClinicalTrials.gov. Number: NCT05405764.

Target Metabolome Profiling-Based Machine Learning as a Diagnostic Approach for Cardiovascular Diseases in Adults.

Metabolomics is a promising technology for the application of translational medicine to cardiovascular risk. Here, we applied a liquid chromatography/tandem mass spectrometry approach to explore the associations between plasma concentrations of amino acids, methylarginines, acylcarnitines, and tryptophan catabolism metabolites and cardiometabolic risk factors in patients diagnosed with arterial hypertension (HTA) (n = 61), coronary artery disease (CAD) (n = 48), and non-cardiovascular disease (CVD) individuals (n = 27). In total, almost all significantly different acylcarnitines, amino acids, methylarginines, and intermediates of the kynurenic and indolic tryptophan conversion pathways presented increased (p &lt; 0.05) in concentration levels during the progression of CVD, indicating an association of inflammation, mitochondrial imbalance, and oxidative stress with early stages of CVD. Additionally, the random forest algorithm was found to have the highest prediction power in multiclass and binary classification patients with CAD, HTA, and non-CVD individuals and globally between CVD and non-CVD individuals (accuracy equal to 0.80 and 0.91, respectively). Thus, the present study provided a complex approach for the risk stratification of patients with CAD, patients with HTA, and non-CVD individuals using targeted metabolomics profiling.

Feeding pigs amino acids as protein-bound or in free form influences postprandial concentrations of amino acids, metabolites, and insulin

Dietary proteins need to be digested first while free amino acids (AAs) and small peptides are readily available for absorption and rapidly appear in the blood. The rapid postprandial appearance of dietary AA in the systemic circulation may result in inefficient AA utilisation for protein synthesis of peripheral tissues if other nutrients implicated in AA and protein metabolism are not available at the same time. The objective of this experiment was to compare the postprandial concentrations of plasma AA and other metabolites after the ingestion of a diet that provided AA either as proteins or as free AA and small peptides. Twenty-four male growing pigs (38.8 ± 2.67 kg) fitted with a jugular catheter were assigned to one of three diets that provided AA either in protein form (INT), free AA and small peptides (HYD), or as free AA (FAA). After an overnight fast and initial blood sampling, a small meal was given to each pig followed by serial blood collection for 360 min. Postprandial concentrations of plasma AA, glucose, insulin, and urea were then measured from the collected blood. Non-linear regression was used to summarise the postprandial plasma AA kinetics. Fasting concentrations of urea and some AA were higher (P < 0.05) while postprandial plasma insulin and glucose were lower (P < 0.01) for INT than for HYD and FAA. The area under the curve of plasma concentration after meal distribution was lower for INT for most AAs (P < 0.05), resulting in a flatter curve compared to HYD and FAA. This was the result of the slower appearance of dietary AA in the plasma when proteins are fed instead of free AA and small peptides. The flatter curve may also result from more AAs being metabolised by the intestine and liver when INT was fed. The metabolism of AA of the intestine and liver was higher for HYD than FAA. Providing AA as proteins or as free AA and small peptides affected the postprandial plasma kinetics of AA, urea, insulin, and glucose. Whether the flat kinetics when feeding proteins has a positive or negative effect on AA metabolism still needs to be explored.

Raw Eggs To Support Postexercise Recovery in Healthy Young Men: Did Rocky Get It Right or Wrong?

Egg protein is ingested during recovery from exercise to facilitate the postexercise increase in muscle protein synthesis rates and, as such, to support the skeletal muscle adaptive response to exercise training. The impact of cooking egg protein on postexercise muscle protein synthesis is unknown. We sought to compare the impact of ingesting unboiled (raw) compared with boiled eggs during postexercise recovery on postprandial myofibrillar protein synthesis rates. In a parallel design, 45 healthy, resistance-trained young men (age: 24 y; 95% CI: 23, 25 y) were randomly assigned to ingest 5 raw eggs (∼30 g protein), 5 boiled eggs (∼30 g protein), or a control breakfast (∼5 g protein) during recovery from a single session of whole-body resistance-type exercise. Primed continuous l-[ring-13C6]-phenylalanine infusions were applied, with frequent blood sampling. Muscle biopsies were collected immediately after cessation of resistance exercise and at 2 and 5 h into the postexercise recovery period. Primary (myofibrillar protein synthesis rates) and secondary (plasma amino acid concentrations) outcomes were analyzed using repeated-measures (time × group) ANOVA. Ingestion of eggs significantly increased plasma essential amino acid (EAA) concentrations, with 20% higher peak concentrations following ingestion of boiled compared with raw eggs (time × group: P < 0.001). Myofibrillar protein synthesis rates were significantly increased during the postexercise period when compared with basal, postabsorptive values in all groups (2-4-fold increase: P < 0.001). Postprandial myofibrillar protein synthesis rates were 20% higher after ingesting raw eggs [0.067%/h; 95% CI: 0.056, 0.077%/h; effect size (Cohen d): 0.63], and 18% higher after ingesting boiled eggs (0.065%/h; 95% CI: 0.058, 0.073%/h; effect size: 0.69) when compared with the control breakfast (0.056%/h; 95% CI: 0.048, 0.063%/h), with no significant differences between groups (time × group: P = 0.077). The ingestion of raw, as opposed to boiled, eggs attenuates the postprandial rise in circulating EAA concentrations. However, postexercise muscle protein synthesis rates do not differ after ingestion of 5 raw compared with 5 boiled eggs in healthy young men. This trial was registered at the Nederlands Trial Register as NL6506 (www.trialregister.nl).

Time Courses of Gastric Volume and Content after Different Types of Casein Ingestion in Healthy Men: A Randomized Crossover Study

Few studies have evaluated differences in the curd-forming ability of casein on gastric volume and content directly after ingestion in humans. This study evaluated the time course of gastric volume and curd conditions in the stomach after protein ingestion. This was an open-labeled, randomized crossover trial. Ten healthy men [age: 33.4 ± 7.3 y; BMI (kg/m2): 21.9 ± 0.9] received 350 g of 3 isonitrogenous and isocaloric protein drinks containing 30 g micellar casein (MCN), sodium caseinate (SCN), or whey protein concentrate (WPC). The gastric antrum cross-sectional area (CSA) and curd in the stomach were measured using ultrasonography within 5 h after ingestion. The differences between test foods were tested using the MIXED model and post hoc tests using Fisher's protected least significant difference. The incremental AUC of the gastric antrum CSA after MCN ingestion was 1.3-fold and 1.5-fold higher than that after the ingestion of SCN and WPC, respectively (both P < 0.05), but not different between SCN and WPC. The number of participants with curds ≥20 mm with a high echogenicity clot observed in the stomach within 5 h after MCN ingestion was significantly greater than that after the ingestion of other proteins (n = 9 for MCN, n = 2 for SCN, and n = 0 for WPC; bothP < 0.01). The regression line slopes on total plasma amino acid concentration and gastric antrum CSA were significantly different between the participants with and without curds. In contrast to SCN and WPC, MCN ingestion resulted in slow kinetics of gastric antrum CSA. Differences in curd formation of casein in the stomach affect gastric emptying and plasma amino acid absorption kinetics after ingestion in healthy men. This trial was registered at University Hospital Medical Information Network Clinical Trials Registry as UMIN000038388 (https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000043746).

Plasma amino acids levels in 1859 physical examination subjects in Hangzhou City in 2020

To study the relationship between fasting plasma amino acids and obesity in the physical examination population. A total of 1859 persons who underwent physical examination in the Second Affiliated Hospital Zhejiang University School of Medicine from January to December 2020 were enrolled. Fasting plasma amino acids concentrations and body fat ratio(BFR) were respectively determined by ultra-performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS) and Inbody instrument. According to body mass index and gender grouping, Python language was used for data analysis and graphic visualization to explore the relationship between body mass index, gender and plasma amino acids levels. The plasma levels of glycine, serine and asparagine in the overweight and obesity groups were significantly lower than those in the normal group, especially the levels in the obesity group were lower than those in the overweight group in males(P&lt;0.05). There was no significant difference in plasma levels of lysine, tryptophan, arginine and hydroxyproline among normal, overweight and obesity groups(P&gt;0.05). The plasma levels of leucine, valine, tyrosine, phenylalanine(in males), isoleucine(in females) and alanine in the overweight and obesity groups were significantly higher than those in the normal group, and the levels in the obesity group were higher than those in the overweight group except alanine(P&lt;0.05). BFR was positively correlated with body mass index. BFR in females increased significantly with age after 50 years old(P&lt;0.05). The rate of overweight and obesity among the health screening population is high.

Methionine and cysteine oxidation are regulated in a dose dependent manner by dietary Cys intake in neonatal piglets receiving enteral nutrition.

Methionine (Met) is an indispensable amino acid (AA) in piglets. Met can synthesize cysteine (Cys), and Cys has the ability to reduce the Met requirement by 40% in piglets. However, whether this sparing effect on Met is facilitated by downregulation of Cys synthesis has not been shown. This study investigated the effects of graded levels of Cys on Met and Cys oxidation, and on plasma AA concentrations. Piglets (n = 32) received a complete elemental diet via gastric catheters prior to being randomly assigned to one of the eight dietary Cys levels (0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.40, 0.50 g kg-1d-1) with an adequate Met concentration (0.25g kg-1d-1). Constant infusion of L-[1-14C]-Met and L-[1-14C]-Cys were performed for 6 h on d 6 and d 8 to determine Met and Cys oxidation, respectively. Met oxidation decreased as Cys intake increased (P<0.05). At higher Cys intakes (0.15 to 0.5g kg-1d-1), Met oxidation decreased (P<0.05) at a slower rate. Cys oxidation was similar (P>0.05) among dietary Cys intakes; however, a significant polynomial relationship was observed between Cys oxidation and intake (P<0.05, R2 = 0.12). Plasma Met concentrations increased (P<0.05) linearly with increasing levels of dietary Cys, while plasma Cys concentrations changed (P<0.05) in a cubic manner and the highest concentrations occurred at the highest intake levels. Increasing dietary levels of Cys resulted in a reduction in Met oxidation until the requirement for the total sulfur AA was met, indicating the sparing capacity by Cys of Met occurs through inhibition of the transsulfuration pathway in neonatal piglets.

Postprandial plasma amino acid and metabolite kinetics of adult and growing pigs fed a diet with a balanced or unbalanced amino acid profile

Feeding diets with an unbalanced amino acid (AA) profile can reduce the postprandial AA utilization for protein synthesis. Growing pigs use dietary AA mainly for protein accretion, whereas non-lactating and non-pregnant adult pigs use AA mainly for maintenance. The requirement for AA for growth is much larger than that for maintenance and growing pigs may therefore be more affected by a diet with an unbalanced AA profile than adult pigs. This study aimed to compare the postprandial plasma AA and metabolite concentrations of adult and growing pigs after feeding a diet with either an unbalanced (UNB) or a balanced AA profile (BAL). The postprandial plasma concentrations of AA were used to study the influence of AA balance on postprandial AA metabolism. Extensively hydrolysed feathers (EHF) were used as an AA source. Both BAL and UNB contained EHF supplemented with L-Ala, L-Asp, L-Glu, Gly, and L-Trp while BAL was also supplemented with L-His, L-Ile, L-Lys, L-Met, and L-Tyr. Four growing and four male adult pigs were fitted with a jugular catheter and received each diet as a meal test thrice. The meal test consisted of giving a small meal after an overnight fast followed by serial blood collection for 360 min. A non-linear regression model was used to describe the postprandial plasma AA kinetics. Plasma kinetics of adult and growing pigs fed BAL resulted in a higher area under the curve (AUC) for the AA that were used to balance the diet. For the other AA, feeding BAL resulted in lower AUC, suggesting faster metabolic utilization of AA for protein synthesis. The apparent quantity of dietary AA appearing in the plasma after feeding was lower in adult pigs, suggesting higher first-pass AA utilization in the intestine and liver. For adult and growing pigs, balancing the AA profile of the diet resulted in faster overall metabolic utilization of AA as seen in the generally lower AUC of BAL compared to UNB.

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.

Analytical Validation of an Assay for Concurrent Measurement of Amino Acids in Dog Serum and Comparison of Amino Acid Concentrations between Whole Blood, Plasma, and Serum from Dogs.

Amino acids play an important role in metabolism. Comprehensive analytical validation of an assay for the concurrent measurement of a large number of amino acids in dogs is lacking, which precludes its usefulness in a clinical setting. Amino acids are often measured in plasma or whole blood. However, serum is commonly used for gastrointestinal diagnostic testing in dogs and is therefore convenient to use. This study aimed to analytically validate an assay for the concurrent measurement of amino acids in dog serum and to evaluate differences in amino acid concentrations in whole blood, plasma, and serum in dogs. Analytical validation of the assay (Biochrom 30+ Amino Acid Analyzer) was performed on fresh or banked serum samples from dogs. Whole blood, plasma, and serum from 36 healthy dogs were analyzed, and concentrations of the three sample types were compared. The assay was demonstrated to be precise, reproducible, accurate, linear, and stable for the measurement of the majority of compounds detected in dog serum. Cystine, glutamic acid, and ethanolamine were shown to be unstable at conditions commonly encountered in clinical settings. Significant differences in concentrations were identified between whole blood, plasma, and serum for 33 of 42 compounds. Amino acid profiles in serum and plasma were more similar to each other than to those in whole blood. While some amino acids are present in similar concentrations in whole blood, plasma, and serum, others are highly dependent on the type of biofluid, and measurements warrant strict adherence to sample type-based reference intervals.

341 Effects of Supplemental Betaine on Protein Deposition and Plasma Amino Acid Concentrations in Growing Steers with Modulated Methyl Group Status

Abstract Methyl group donors (e.g., methionine, betaine) may improve performance of growing beef cattle. Our objective was to evaluate effects of betaine supplementation on protein deposition and plasma amino acids in growing steers with altered methyl group status. Seven ruminally cannulated Holstein steers (189 kg) were used in a 6×6 Latin square design with 10-d periods. Factorial treatments were continuously infused abomasally and included 3 methyl group modulators [MGM; control; 15 g/d guanidinoacetic acid (GAA); or 16.8 g/d creatine] and 2 levels of betaine (0 or 5.7 g/d betaine). Supplemental GAA or creatine increases body creatine supply; however, GAA consumes methyl groups during creatine synthesis, whereas creatine spares methyl groups by reducing GAA synthesis. Steers received 3.5 kg/d (DM basis) of a corn-based diet. Total collection of urine and feces occurred on d 7 through 9 to measure N retention. Jugular blood was collected on d 10. No interactions between MGM or betaine were observed (P≥0.17). Betaine supplementation increased retained N (P=0.03), but did not affect urinary or fecal N excretion (P≥0.16). Betaine increased plasma Met (P=0.03) and cystine (P=0.04) and tended to decrease plasma Lys (P=0.10). Nitrogen retention was not affected by MGM (P=0.63). Creatine increased urinary N (P=0.04), and GAA tended to increase urinary N (P=0.08). Creatine increased fecal N excretion relative to control (P=0.02); GAA also increased fecal N relative to control (P&amp;lt; 0.01). Plasma Met was not affected by MGM (P=0.41). Plasma cystine was decreased by creatine relative to control (P=0.01), but was not affected by GAA relative to control (P=0.26). Plasma Lys was decreased by GAA (P&amp;lt; 0.01) and creatine (P=0.05) relative to control. Supplemental betaine improved protein deposition in growing steers and altering methyl group status affected plasma amino acid concentrations.

Elevated branched-chain amino acid inclusions generate distinctly divergent growth performance responses in broiler chickens offered wheat- and/or sorghum-based, reduced-crude protein diets

The objective of this study was to determine the effects of elevated branched-chain amino acid (BCAA) inclusions in 187.5 g/kg crude protein (CP) diets based on wheat, sorghum or a wheat-sorghum blend on performance parameters of broiler chickens from 7 to 28 days post-hatch. The first tier of BCAA inclusions relative to lysine were leucine 105, isoleucine 65 and valine 75. The second tier was an elevation of leucine to 150 individually and in the third tier leucine was maintained at 150 and isoleucine and valine were elevated to 75 and 85, respectively. A 3 × 3 factorial array of these dietary treatments were offered to a total of 324 male Ross 308 broiler chickens housed in six replicate cages per treatment with six birds per cage. The assessed performance parameters included growth performance, relative abdominal fat-pad weights, nutrient utilisation, apparent jejunal and ileal digestibility coefficients of starch, protein (N) and amino acids and free amino acid concentrations in systemic plasma. Treatment interactions were observed for weight gain (P < 0.001) and FCR (P < 0.014). Elevated BCAA inclusions in sorghum-based diets significantly increased weight gain by 9.26 % (1451 versus 1328 g/bird) and numerically improved FCR by 0.86 % (1.378 versus 1.390). In contrast, elevated BCAA inclusions in wheat-based diets significantly depressed both weight gain by 9.49 % (1288 versus 1423 g/bird) and FCR by 8.33 % (1.665 versus 1.537). Wheat-based diets (5.68 g/kg) generated significantly lighter relative abdominal fat-pad weights than either sorghum-based (13.48 g/kg) or blended diets (12.95 g/kg). Sorghum-based and blended diets supported superior energy utilisation and N retention in comparison to wheat-based diets. Similarly, sorghum-based and blended diets supported higher jejunal and ileal starch digestibility coefficients than wheat-based diets, but wheat supported significantly higher jejunal protein (N) digestibility by 10.5 % (0.726 versus 0.657). Treatment interactions were observed for ileal digestibility of 4 amino acids (arg, lys, val, gly), BCAA inclusions significantly influenced 3 amino acids (ile, leu, thr) and the feed grain significantly influenced 10 amino acids (his, ile, leu, met, phe, ala, asp, glu, pro, tyr). Elevating BCAA inclusions in wheat-sorghum blended diets significantly increased free plasma concentrations of leucine and influenced concentrations of isoleucine and valine. However, BCAA inclusions significantly decreased plasma concentrations of threonine, asparagine plus aspartic acid, cysteine, glycine, proline, and serine. Consideration is given to possible reasons for the remarkable weight gain treatment interaction following elevated BCAA inclusions to sorghum- or wheat-based diets.

L-Leucine supplementation reduces growth performance accompanied by changed profiles of plasma amino acids and expression of jejunal amino acid transporters in breast-fed intra-uterine growth-retarded piglets.

Previously, we provided an evidence that l-Leucine supplementation facilitates growth performance in suckling piglets with normal birth weight. However, it remains hitherto obscure weather breast-fed piglets displaying intra-uterine growth restriction (IUGR) show a similar effect in response to l-Leucine provision. In this study, 7-d-old sow-reared IUGR piglets were orally administrated with l-Leucine (0, 0·7, 1·4 or 2·1 g/kg BW) twice daily for 2 weeks. Increasing leucine levels hampered the growth performance of suckling IUGR piglets. The average daily gain of IUGR piglets was significantly reduced in 1·4 g/kg BW and 2·1 g/kg BW l-Leucine supplementation groups (P < 0·05). Except for ornithine and glutamine, the plasma concentrations of other amino acids were abated as l-Leucine levels increased (P < 0·05). Leucine supplementation led to reduction in the levels of urea, blood ammonia, blood glucose, TAG and total cholesterol, as well as an elevation in the level of LDL-cholesterol in suckling IUGR piglets (P < 0·05). In addition, 1·4 g/kg BW of l-Leucine enhanced the mRNA expression of ATB0,+, whereas decreased the mRNA abundances of CAT1, y + LAT1, ASCT2 and b0,+AT in the jejunum (P < 0·05). Concomitantly, the jejunum of IUGR piglets in l-Leucine group contains more ATB0,+ and less SNAT2 protein than in the control (P < 0·05). Collectively, l-Leucine supplementation impairs growth performance in breast-fed IUGR piglets, which may be associated with depressed nutritional conditions and alterations in the uptake of amino acids and the expression of amino acid transporters in the small intestine.

Four weeks treatment with the GLP-1 receptor analogue liraglutide lowers liver fat and concomitantly circulating glucagon in individuals with overweight.

We investigated the effect of pharmacologically induced weight loss on markers of glucagon resistance in individuals with overweight during treatment with the glucagon-like peptide-1 receptor agonist liraglutide. We performed an open-label study in 14 men with overweight (age 38 ± 11 years, BMI 32 ± 4 kg/m2) without simultaneously diabetes. Subjects were treated with liraglutide, initiated and titrated with 0.6 mg/day/week to reach the final dose of 3.0 mg/day. Subjects were examined at baseline, during titration (Week 4), after 2 weeks of steady state (Week 6) of final dosing of liraglutide and 3 weeks after discontinuation of liraglutide (follow-up). Study participants lost 3.3 ± 1.9 kg (3%) total body weight during the first 4 weeks of treatment with liraglutide. Simultaneously, liver fat content decreased from 12.4 ± 11.6% to 10.2 ± 11.1%, p = 0.025, whereas fat content in the spleen and subcutaneous tissue was unaltered. Markers of glucagon resistance, including plasma glucagon and the glucagon-alanine-index, also decreased significantly during treatment, but total and individual plasma amino acid concentrations did not. Insulin resistance (HOMA-IR) was unchanged during treatment, whereas insulin clearance increased. Treatment with the GLP-1 receptor analogue liraglutide decreased liver fat content, and simultaneously attenuated glucagon concentrations and the glucagon-alanine index in individuals with overweight without diabetes.

Dietary choline supplementation increases the plasma concentration of several amino acids during atherosclerosis development

Background and Aims : Increased dietary intake of choline worsens the development of atherosclerosis in ApoE-KO mice. Gut microbial metabolism of choline results in the production of trimethylamine, which, upon intestinal absorption is converted into the pro-atherogenic molecule trimethylamine-N-oxide (TMAO) in the liver. In this study we investigated if additional endogenous plasma metabolites were modulated by increased choline intake.