Biochemical and physiological bases for utilization of dietary amino acids by young Pigs

Protein is quantitatively the most expensive nutrient in swine diets. Hence it is imperative to understand the physiological roles played by amino acids in growth, development, lactation, reproduction, and health of pigs to improve their protein nutrition and reduce the costs of pork production. Due to incomplete knowledge of amino acid biochemistry and nutrition, it was traditionally assumed that neonatal, post-weaning, growing-finishing, and gestating pigs could synthesize sufficient amounts of all ＂nutritionally nonessential amino acids＂ （NEAA） to support maximum production performance. Therefore, over the past 50 years, much emphasis has been placed on dietary requirements of nutritionally essential amino acids as building blocks for tissue proteins. However, a large body of literature shows that NEAA, particularly glutamine, glutamate, arginine and proline regulate physiological functions via cell signaling pathways, such as mammalian target of rapamycin, AMP-activated protein kinase, extracellular signal-related kinase, Jun kinase, mitogen-activated protein kinase, and NEAA-derived gaseous molecules （e.g., nitric oxide, carbon monoxide, and hydrogen sulfide）. Available evidence shows that under current feeding programs, only 70% and 55% of dietary amino acids are deposited as tissue proteins in 14-day-old sow-reared piglets and in 30-day-old pigs weaned at 21 days of age, respectively. Therefore, there is an urgent need to understand the robes and dietary requirements of NEAA in swine nutrition. This review highlights the basic biochemistry and physiology of absorption and utilization of amino acids in young pigs to enhance the efficacy of utilization of dietary protein and to minimize excretion of nitrogenous wastes from the body.

Branched-chain amino acids supplementation has beneficial effects on the progression of liver cirrhosis:A meta-analysis

BACKGROUND Liver cirrhosis(LC)is currently the 11^(th) most common cause of death and 15^(th) cause of morbidity globally.The treatment of LC is mainly aimed at etiological intervention,lifestyle intervention,prevention and treatment of complications and nutritional treatment.Nutritional treatment of LC mainly includes increasing dietary intake,food intake time and branched-chain amino acids(BCAAs).Despite the recommendation of BCAAs in some guidelines,adverse effects have been reported in studies so the efficacy and safety of BCAAs remain controversial.Currently,BCAAs have been widely used in chronic liver disease,while the summary of the effect of BCAAs on long-term prognosis is rare.AIM To determine the effects of BCAAs in patients with LC.METHODS The PubMed,Cochrane Library,Embase and Web of Science databases were searched.The retrieval deadline was 1 October 2021 and there were no language restrictions set in the retrieval.The study was performed in strict accordance with the inclusion and exclusion criteria.Nine studies were finally included.The primary outcome was complications of LC.The secondary outcomes were nutritional status and liver function.This meta-analysis used the Review Manager,version 5 statistical package(Cochrane Collaboration,Oxford,England)for analysis.RESULTS The analysis included nine studies that consisted of 1080 patients(554 in the BCAA groups and526 in the control groups).The nine studies were randomized control trials(RCTs).The quality of the studies was assessed using the risk of bias method recommended by the Cochrane Collaboration.BCAAs reduced the rate of complications in LC patients[Risk ratio:0.70,95%confidence interval(CI):0.56-0.88,P=0.002]and improved patients’albumin levels[std mean difference SMD:0.26,95%CI:0.12-0.40,P=0.0002].Meanwhile,BCAAs significantly ameliorated the levels of alanine transaminase(SMD:-2.03,95%CI:-2.52 to-1.53,P<0.00001)and aspartate aminotransferase(SMD:-1.8,95%CI:-2.14 to-1.46,P<0.00001).Meanwhile,glucose in the LC was significantly increased in BCAA-treated patients(MD:13.04,95%CI:6.81-19.89,P=0.0002).CONCLUSION BCAAs reduce the incidence of complications in patients with LC and ameliorate nutritional status.

Effects of Branched-chain Amino Acids on Nutritional Metabolism and Pharmacoeconomics in Patients with Severe Abdominal Trauma

Objective:To observe the influences of branched-chain amino acids(BCAAs)on nutrition metabolism and prognosis of patients with severe abdominal trauma;at the same time,to analyze and evaluate the pharmacoeconomics of it.Methods:A total of 75 severe abdominal trauma patients were recruited from June 2016 to December 2017 and randomly divided into control group and observation group.After surgery and basic treatment,parenteral nutrition support therapy with iso-nitrogen and iso-calorie of both groups was administered.Meanwhile,an equivalent of 8.5%(18AA-Ⅱ)and 10%(20AA)compound AA injection was administrated to the control and observation groups,respectively.The nitrogen balance,serum protein level and plasma amino spectrum of the patients were observed before and after treatment.Besides,the hospital stay,survival rate,complications,adverse reactions and hospitalization costs were also compared.Results:After a 7-day course treatment,the nitrogen balance level of the two groups was significantly improved,but no significant difference was found between them.In addition,the serum protein level and plasma amino spectrum of the two groups was generally improved when compared to before treatment.Compared with the control group,the level of albumin and transferrin in the observation group was improved significantly after treatment,while no difference in plasma amino spectrum was found between the two groups.Moreover,the cost analysis showed remarkably reduced hospitalization costs in the observation group.Conclusion:To a certain degree,BCAAs could improve the nutritional metabolism and prognosis of patients with severe abdominal trauma,and have good cost-effectiveness.

Determinations of Amino Acids and Fatty Acids Levels in Date Palm Kernel Flour in Sudan

The aim of this study was the determination of various levels in date palm kernel(DPK)flour for enhancing production performance of animals natural feed in Sudan,in addition to protecting the environment from waste.The material used is flour of date seeds from the following date varieties:Berkawi,Gandilla,Tamouda,Klmah,Mashreq Wad Khatib,Mashreq Wad Lagi.This research was conducted at the following institutions:Geological Research Authority of Sudan,preparation of the DPK;Institute Penyelidikan Produk Halal of University Putra Malaysia,determination of amino acids using high performance liquid chromatography mass spectroscopy mass spectroscopy(HPLC MSMS)fluorescence;University of Medical Sciences and Technology-Sudan,determination of fatty acids using gas chromatography-mass spectrometry(GC-MS).Seeds were collected from various areas of Sudan and from factories.All seeds were mixed together and they weigh 8 kg.Sample preparation includes five steps,namely(1)washing,(2)soaking,(3)flushing,(4)drying,(5)grinding.The flour was then used to determine its contents of amino acids by high performance liquid chromatography-fluorescence detector(HPLC-FLD)and fatty acids by GC-MS.Concentrations of the following amino acids were determined in the sample(percentages in w/w are indicated between parenthesis):hydroxyprofine(0.224),aspartic acid(7.029),serine(6.350),glutamic acid(1.745),glycine(3.183),histicline(0.705),arginine(7.262),threonine(ND),alanine(15.558),proline(4.302),cysteine(34.326),tyrosine(2.070),voline(0.402),methionine(2.989),lysine(4.723),isoleucine(2.203),leucine(4.485),phenylalanine(2.442)while the determined fatty acids are:lauric acid(11.765),tetradecanoic acid(14.214),methyl palmitoleate(16.235),palmitic acid(16.431),cis-10-Heptadecenoic acid,methyl ester(17.253),margaric acid(17.464),linoleic acid(18.183),oleic acid(18.236),stearic acid(18.449),methyl ester(20.106)and arachidic acid(20.308).The seeds of the dates are found to be rich in amino acids as well as fatty acids,which means they can be used as natural feed for animals.These seeds are now dealt with as waste so using them as source of nutrition means protecting the environment and also reducing the cost of animal feed.

Identified Analytical Profile for Microelements, Trace Metals, Amino Acids and Screening of Anti-Diabetic Activity from Flower and Leaf Extracts of Moringa oleifera in Streptozotocin (STZ)-Induced Diabetic Rats

Background: Moringa oleifera plant is popularly known for its rich phytoconstituents and nutritional value and important medicinal values in both traditional and modern systems of medicine. We explored the present study for measurements of microelements, amino acid, phenolic content in hydro-al-coholic flower and leaf extracts of Moringa oleifera along with anti-diabetic activity in Streptozotocin (STZ)-induced diabetic male Wistar rats. Methodology: The micronutrients were determined by using atomic absorption spectrophotometer at 285 nm and 422 nm for Calcium (Ca), phosphorus (P), Iron (Fe), and Zinc (Zn), etc. The trace elements were also measured by spectrophotometer. The essential amino acid was determined by using Amino acid analyser. The total phenolic content in hydro-alcoholic extracts (flower and leaf) M. oleifera measured the absorbance at 760 nm by UV spectrophotometer. The screening of anti-diabetic activity HAFE and HALE of Moringa oleifera at two different dose of 100 and 200 mg/kg b.w. for 21 days were performed by determining the changes in biochemical parameters. Result and Discussion: The results revels that the presence of micronutrients, trace elements and amino acids in both flower and leaf of M. oleifera. The hydrolaocholic extracts of HAFE and HALE at 200 mg/kg b.w. showed significant antidiabetic activity compared with standard Glibenclamide. Whereas dose at 100 mg/kg b.w. showed moderate activity. Conclusion: In conclusion, the M. oleifera exhibits more effectiveness against STZ-induced diabetes. The HAFE and HALF extracts exhibited significant anti-diabetic property and active components may be isolated and clinical studies is required for further evaluation. Because of the rich source of phytoconstients, nutritional elements will be helpful in processed food products as dietary supplements especially for malnutrition in children in the current era.

Differences in the Content of Protein and Essential Amino Acids between Different Rice Varieties

Evaluation of the protein content is a major indicator of the nutritional quality of rice,and the protein quality of rice is the best among cereal crops. Essential amino acids play an irreplaceable role in human growth,development and health care. Essential amino acid is a key ingredient to measure the nutritional value of rice. Using the experimental rice processed from the rice variety " Yuzhenxiang" sprayed with plant nutrients( patent number: ZL201110103910. 9),namely high essential amino acid nutritional rice,combined with five kinds of high quality rice imported by COFCO and homegrown " Wuchang rice",we send the samples of the seven kinds of rice to Hunan Food Testing Center,and adopt HPLC method to test the content of protein and eight kinds of essential amino acids. Three bags of rice are randomly selected for each kind of rice,and each bag is a replication. The test results show that there are highly significant differences in the content of essential amino acids between different kinds of rice( F = 246. 29**,P =5 ×10- 71),and there are also highly significant differences in the content between different kinds of essential amino acids( F = 3937. 09**,P = 4 × 10- 146). The test results of protein content indicate that there are highly significant differences in the content of protein between different kinds of rice( F = 3937. 0973. 29**,P =5. 81 ×10- 11),and the test results of lysine content show that there are highly significant differences in the content of lysine between different kinds of rice( F =3937. 0973. 29**,P =5. 81 ×10- 11).

Assessment of Gross Chemical Composition, Mineral Composition, Vitamin Composition and Amino Acids Composition of Wheat Biscuits and Wheat Germ Fortified Biscuits

Wheat germ is reckoned valuable healthful functional food. The present investigation was performed to assess nutritional status of wheat biscuits and wheat germ fortified biscuits. Study included determination of gross chemical composition, caloric value, minerals (Mn, Ca, Fe, Cu, P, Na and K), vitamins (C, Folic acid, A, and E), and amino acid composition of wheat biscuits and 15%, 20% wheat germ fortified biscuits. Likewise physical and sensory characteristics of studied biscuits were assessed. The data revealed that 20% wheat germ fortified biscuits proved to be nutritious functional healthful food. It improved both physical, sensory characteristics and recorded the highest crude protein (12.20%), crude fiber (2%), and the least fat (9.63%), moisture (3.01%), and caloric value (436.31 Kcal/100g). While it recorded the highest Mn and Cu contents as well as increased vitamins C, Folic acid, A, and E. Besides, 20% wheat germ fortified biscuits increased all the eight essential amino acids contents resulting in an improvement of the nutritive value of wheat biscuits. Therefore it could be recommended for caloric reduced diets for obese and overweight persons. Likewise, it should be increasing interest as an ingredient in the industry as functional and healthy foods formulations as biscuits, bread and cakes.

DETERMINATION OF AMINO ACIDS IN TWO POLYSIPHONIA SPECIES AND STUDY OF ENZYMATIC HYDROLYSIS METHOD

The total content of the rich amino acids in two common red algae, Polysiphonia urceolata and Polysiphonia japonica growing in the Qingdao seashore were determined. The algae powder was hydrolyzed by 6 mol/L HCl at 110℃ for 48 h and determined by amino acid analyzer. The content was 25.35% and 24.16%, respectively, much higher than that of some other species. In addition, a nutritive liquid with abundant amino acids was prepared (by the enzymatic hydrolysis method using Polysiphonia urceolata ) as raw material for a kind of health beverage. The dried seaweed was decolored by 0.25% KMnO 4 and 0.5% active carbon, then enzymalized. In the selection of enzymalizing condition, the orthogonal experimental design was used. Four factors including kinds of enzyme, quantity of enzyme, temperature and time were studied at 3 levels. According to the orthogonal design results, we can choose an optimal condition: hydrolyzing at 45℃ by neutral proteinase (0.25%, w/w) for 2 h, adjusting pH to 8.5, then adding trypsin (0.25%, w/w) and hydrolyzing for 2 h. Finally the above solution was alkalized by NaOH and neutralized by casein. After the hydrolyzed liquid was filtered and concentrated, suitable additives were added. The final products contain rich amino acids.

Amino Acids during Perioperative Period

During anesthesia, thermoregulation is impaired and hypothermia will frequently occur in most patients. Hypothermia affects immunologic activity, bleeding tendency and the recovery from anesthesia. Therefore, it may prolong hospital stay, and increase morbidity, e.g. surgical site infections, cardiac events and multiple organ dysfunctions in trauma. External warming is often used to prevent hypothermia. However, infusion of amino acids is also valuable to prevent hypothermia due to their enhanced thermogenic action under anesthesia. During surgery, amino acids administration would maintain the body homeostasis, and counteract the disadvantageous fasting metabolism. Postoperatively, amino acids may be advantageous for the healing of the surgical wound. Thus, appropriate nutritional management, including glucose, during the perioperative period would prevent catabolism, frequently occurring after surgery. Protocols like ERAS (Enhanced Recovery After Surgery) are proposed for quick recovery after surgery. ERAS protocol recommends preoperative carbohydrate and early enteral nutrition, but does not include infusion of amino acids during the perioperative period. During prolonged surgery, patients clearly need good nutritional support. In this article, we intend to describe the problems of hypothermia briefly, and explain the mechanism of amino acids in hypothermia prevention. In addition, we address some evidences of nutritional management during the perioperative period.

Effect of perioperative branched chain amino acids supplementationin liver cancer patients undergoing surgical intervention: Asystematic review

performed independently by authors(Yap KY,Chi H,Ng S)identified 50 studies for full-text evaluation.Finally,12 prospective RCTs and 4 non-randomised studies(1 non-randomised trial and 3 observational studies)were included.A detailed PRISMA diagram is shown in Figure 1.The studies included were assessed for risk of bias,with a summary of the assessment shown in Figure 2 and Table 1 for trials and non-interventional studies,respectively.The PRISMA checklist is appended in Supplementary Figure 1.

Recent Advances in Swine Amino Acid Nutrition

Recent advances in swine protein nutrition are characterized by the development of functional a- mino acids （AA） in regulating fetal and postnatal survival, growth and development. These AA include arginine, glutamine, glutamate, proline, leucine, cyste- ine and tryptophan. Due to limited knowledge on AA nutrition, pork producers have traditionally paid little attention to supplementing the arginine family of AA to swine diets. Results of recent studies indicate that functional AA serve important regulatory functions in nutrient metabolism, protein turnover, and immune function, therefore enhancing efficiency of feed utili- zation by pigs. The underlying mechanisms include activation of nitric oxide, mammalian target of rapam- ycin, gaseous signaling, and AMP-activated protein ki- nase pathways, as well as anti-oxidative function. Di- etary supplementation with arginine, glutamine, pro- line or leucine to weanling piglets enhances theirgrowth performance. Arginine or glutamine is also ef- fective in increasing milk production by lactating sows. Furthermore, supplementing arginine to the diet of pregnant gilts between days 30 and 114 of gestation increases the number of live-born piglets and litter birth-weight. Availability of feed-grade functional AA holds great promise for improving animal health and nutrient utilization in pig production worldwide. Addi- tionally, feedstuffs of animal origin [ e. g. , blood meal （ ring dried ）, feather meal （ hydrolyzed ）, meat and bone meal, porcine protein meal, and poultry by-prod- uct meal （both feed- and petfood-grades） ] are excel- lent and cost-effective sources of both essential and functional AA for formulating balanced swine diets. New knowledge on AA nutrition provides a much needed scientific basis for revising the next edition of swine nutrient requirements.

Amino acid profiles and protein quality of Siberian apricot(Prunus sibirica L.)kernels from Inner Mongolia

Siberian apricot(Prunus sibirica L.)is a traditional nut tree species in East Asia and Siberia and is a possible contribution to healthy diets.However,it has attracted little research attention and information on the nutritional value of its kernel is limited.In this study,the profile,nutritional value and variation of amino acids were investigated in eight provenances.The kernels contained29×10-2 g/g protein and were rich in glutamic acid(26.5%),aspartic acid(11.3%)and arginine(10.1%).They showed higher essential amino acids(EAA)than similar protein values for almonds.The variation coefficients of amino acids ranged from 3.8 to 43.7%,and the levels of seven amino acids were significantly different among the eight provenances.The proportion of essential amino acids to total amino acids and amino acid score were also quite different.Protein was negatively correlated with some amino acids and protein quality values.In conclusion,there were two superior provenances(Wanjiagou and Horinger County)with high EAA contents and protein quality,and could be used in the large-scale development of this species.

Free Amino Acid Profiles of Fermented Soybean Products Prepared by Bacillus subtilis and Rhizopus oligosporus

Fermented soybean is one of the traditional foods widely consumed in many Asian countries. Most products（i.e., Natto, Jang, Kinema and Thua nao） are produced mainly by the bacterial activity. This study was performed as a part of the program to improve the soybean fermentation, and a use of the co-culture between the bacterium Bacillus subtilis and the fungus Rhizopus oligosporus was selected. For fermentation, the raw soybeans were washed, sterilized by autoclaving, and inoculated with a mixed microbial starter culture of B. subtilis（102 CFU · g-1） and R. oligosporus（102 conidia · g-1）. The Free Amino Acid（FAA） contents were then investigated by using High Performance Liquid Chromatography（HPLC）. The results showed that the amounts of FAAs and essential amino acids in the fermented soybean samples were found at significantly higher concentration when compared to those of the cooked, non-fermented soybean samples（p〈0.05）. These data indicated that an involvement of microbial fermentation helped to accelerate an increase of FAA. The food compositional data were useful as a reference（and/or guidance） for the nutritional value, when compared to other fermented soybeans and related products.

Low Light During Grain Filling Stage Deteriorates Rice Cooking Quality, but not Nutritional Value

To investigate the effect of low light （LL, 50% natural light） during grain filling （GF） stage on rice transamination, amino acid （AA） accumulation, nutritional value, and cooking quality in three different rice genotypes, transaminase activities and AA levels in grains during GF stage and the traits that significantly affected rice quality （physical appearance, cooking quality, and nutritional value） were analyzed. LL did not disturb transamination in rice grains during GF stage, as minimal impact was found on alanine and aspartate transaminase activities. Nevertheless, most AAs in caryopses, including lysine and threonine, increased in response to LL, except for sulfur-containing AAs. These results suggest that AA metabolism and accumulation in rice grains were rarely suppressed by LL during GF stage. Rice nutritional ingredients at harvest, such as major protein components including glutelin and most important essential amino acids （EAAs） including lysine and threonine, increased significantly in response to LL, whereas most protein and EAA ratios were rarely affected. However, LL markedly affected physical appearance of rice grains by reducing brown rice rate, milled rice rate, and 1000-grain weight and increasing the chalkiness rate. In addition, cooking qualities decreased in response to LL, while breakdown values and amylose levels decreased and setback values increased. We concluded that LL during GF stage decreased the cooking quality of rice, but could potentially improve the nutritional value of rice.

Extraction Behavior and Wastewater Treatment of Amino Sulfonic Acid with Alamine 336

p-Amino benzene sulfonic acid (PABSA) is selected as the solute with amphoteric functional group, Lewis acid and Lewis base, to be separated from its dilute solutions. An aliphatic, straight chain amine, Alamine 336 , is used as the extractant, and kerosene, 1-octanol, chloroform, butyl acetate and benzene as the diluent. The effects of pH value of solution, extractant concentration, salt and types of diluent on the distribution coefficient, D, are studied. There is a peak of D value with pH value of solution, the polar diluents are favorable for extracting PABSA, and the salt in aqueous phase reduces values of D apparently. The extraction equilibrium is described using the mass action law, and the calculated data according to the proposed model agree with the experimental data well. Further, the extraction behavior for other amino benzene sulfonic acids, l-amino-8-naphtol-3,6-disulfonic acid (H acid) and 4,4'-diaminostilbene-2,2'-disulfonic acid (DSD acid), is investigated in a wide pH value region. Finally, H acid and DSD acid are successfully removed from wastewater by the extraction with Alamine 336.

Is branched-chain amino acid nutritional supplementation beneficial or detrimental in heart failure?

Sarcopenia or cachexia is often complicated in heart failure.Nutritional support,particularly branched-chain amino acid(BCAA)supplementation,is a candidate treatment for improving sarcopenia or cachexia in elderly patients.However,the efficacy of BCAA supplementation in patients with heart failure has not been established,and the issue is comparatively more complex.Indeed,there are conflicting reports on the efficacy of BCAA supplementation.The evidence for including BCAA supplementation in treating patients with heart failure was reviewed,and the complexity of the issue was discussed.

Early administration of branched-chain amino acid granules

The effect of malnutrition on survival in patients with decompensated liver cirrhosis has not been well defined. Nutritional intervention with branched-chain amino acid (BCAA) can increase serum albumin concentration in patients with decompensated cirrhosis but its effects on survival are unclear. The BCAA to tyrosine ratio (BTR) is a surrogate marker (the normal range of BTR is between 4.41 and 10.05, and a Fischer's ratio of 1.8 corresponds to a BTR of 3.5) in patients with decompensated liver cirrhosis, and BCAA inhibits hepatic carcinogenesis in patients with compensated cirrhosis. This review discusses data regarding the effect of early administration of BCAA granules based on the ratio of BCAA to BTR on prognosis in patients with cirrhosis.

Amino Acid Composition of Cowpea (<i>Vigna ungiculata</i>L. Walp) Flour and Its Protein Isolates

The study of the nutritive value of Cowpea (Vigna ungiculata L.) legume seed is needed, as this legume is a food source in many developing countries. Whole Cowpea Flour (WCF), Dehulled Defatted Cowpea Flour (DDCF), and Cowpea Protein Isolates (CPI) prepared using Isoelectric method (CPII) and using Micellization method (CPIM) are studied. In proximate analysis, the protein content of WCF, DDCF, CPIA and CPIB was found to be 22.3, 26.7, 750 and 76.0 g/100 g, respectively. Net protein value (NPV) was 17.62 for DDCF. Chemical score was 0.66% for DDCF and 112%, 104% for CPII and CPIM, respectively. The first limiting amino acid was cystine for DDCF and threonine for CPII and CPIM. Methionine was found to be the most concentrated essential amino acid in both CPII and CPIM;values were 27.22 and 30.60 g/16 g N, respectively, while lysine was the most abundant essential amino acid in DDCF (4.28 g/16 g N). Essential amino acids of CPIi and CPIM were 22.99 and 15.78 g/16 g N respectively, higher than FAO/WHO reference.

Estimate of Amino Acid Balance in Nutrition

A new chemical index-imbalance degree (IBD), was proposed on the basis of cluster analysis in multivariate statistical analysis to estimate the extent of amino acid balance in protein. The range of IBD is between 0 and 1, successively corresponding to complete balance and entire imbalance for the amino acid profile of a sample. The amino acid increment model of IBD belongs to an asymmetrical maximum-type, and there is a high correlation between IBD and coefficient of variation (CV). The nutritional value of individual feed can be ranked and clustered according to its IBD; and by calculating the IBD of amixed sample with two or more feedstuffs, it is Possible theoretically to predict whether a synergetic. pheno men on exists and when an optimal mutual complement can happen. If the conceptive frame of IBD extended, it can be used to study the balance of nutrients besides amino acids, and is helpful to realize the automatic distinction and selection in diet formulating.

Increased Nitrogen Retention after Trans-Operative Intravenous Amino Acid and Glucose Infusion, without Changes in Urinary Amino Acid, Adrenaline and Plasma Urea or Glucose

Objective: Nutritional deficiencies are associated with increased morbidity and mortality during and after surgery. The present study evaluated nitrogen retention after transoperative intravenous infusion of amino acids and glucose. Design: Prospective study. Setting: Large community hospital. Patients: 18 randomly chosen patients undergoing medium or major surgeries. Interventions and Measurements: The experimental design included a 12-hour period before surgery (P1), a trans-operative period of 6 hours (P2), an early postoperative period (P3, 18 hours), and a late postoperative period (P4, 24 hours). Urinary amino acid and nitrogen were analyzed from P1 through P4. Group I, nine patients, received Ringer’s lactate solution with 5% glucose, and Group II, another nine patients, received a 6.6% amino acid and 16.6% glucose solution over a 6-hour trans-operative period (P2) starting from the anesthesia procedures. All surgical procedures lasted a maximum of 3 hours. Results: There was no statistically significant difference in urinary amino acid or adrenaline excretion between P1 and P4 in either group. Nitrogen excretion values were also similar for both groups, i.e., 0.39 ± 0.16 and 0.39 ± 0.28 g/hour, respectively. The nitrogen balance showed greater nitrogen retention (﹣0.25 ± 0.24 g/hour) in the group receiving the amino acid infusion compared to the group receiving Ringer’s lactate solution (﹣0.59 ± 0.26 g/hour) (P < 0.05). Blood plasma urea nitrogen and glycaemia did not increase at the end of the study (P4 period) in either group. Conclusion: These data indicate that trans-operative infusion of glucose and amino acids can be beneficial for patients submitted to surgical stress in terms of nitrogen retention.