The Analysis On The Synthesis Kinetics Of Plasma Immunoglobulin G In Healthy Young Men Under Control Of Lysine Intake

PurposeIn this study,healthy young men were selected as the research subjects,and the stable isotope tracer technology and 2H2O as the tracer agent were used to conduct human experiments to study the effect of controlled lysine intake on the synthesis kinetics of plasma immunoglobulin G.At the same time,will this stage research results and the daily lysine intake of healthy young men under nutrition intake,concentration of serum IgG and synthetic rate comparison,to discuss whether the lysine intake of established to satisfy the Chinese healthy young men daily physiological needs,in order to further explore the crowd dietary amino acid intake recommendations provide theoretical basis.MethodsRecruit 5 healthy young men who are engaged in light physical activities,aged 21 to 25 years,18.5≤BMI<24.No past medical history,no bad eating habits,smoke-free wine hobbies,normal indicators of physical examination.The lysine intake level was controlled to 70 mg/(kg·d),and the recipe was formulated with reference to the Chinese Dietary Guidelines 2016.The experiment was divided into 10 consecutive cycles,each of which was 7 days.The first 5 weeks were the dietary adaptation period,and during the 6-10 week experimental period,the subjects were orally fed with purified water containing 70%2H2O.On the first day of the sixth week,60%2H2O was orally administered 60 mleach time,and the labeling was performed 6 times.Within the next 5 weeks,subjects were orally administered 70%2H2O twice daily.The fasting body weight was measured in the early morning of the seventh day of the week,and the body mass index(BMI),body fat percentage,muscle rate,and basal metabolic energy consumption were measured by a body composition analyzer.Diet samples were collected in duplicate meals to determine the levels of lysine,fat,protein,carbohydrates,and ash in the diet The measured data was analyzed by analysis of variance to determine whether there were differences in the indicators during the experimentOn the seventh day of each week,15 mL of fasting venous blood was collected from the subjects,plasma immunoglobulin G was purified,identified,hydrolyzed,2H-alanine was derivatized,and 2H-alanine in plasma IgG was detected by GC-MS.Abundance of plasma free 2H-alanine.The plasma IgG synthesis rate was calculated,and the IgG synthesis kinetics equation was plotted.The results of this study were compared with the daily dietary status indicators.Paired t-test was used to analyze whether the indicators before and after the intervention had significant differences,and whether the lysine intake of 70 mg/(kg·d)was satisfied.The tester needs physiological.ResultsThe average actual intake of lysine in this study was 68.06 mg/(kg*d),and the energy was 2628.24 kcal.The average intake of the three major nutrients was:protein 87.40±4.99g/d,fat 71.35±3.81g/d,carbohydrate 407.22±16.53g/d.Under this dietary intake,the average body mass index of the five subjects before and during the experiment was 22.31 ± 1.41 kg/m2;the average fat rate was 22.55±3.42%;the average muscle rate was 36.50±3.73%;the average basal metabolism was 1537.10±107.34kcal./d,all indicators fluctuated within the normal range,and there was no significant change(P>0.05).The plasma total protein concentration of the five subjects before and after heavy water labeling was 72.41 ±8.38 mg/ml,no statistical difference(P>0.05).The plasma IgG concentration was 8.09±0.69 mg/ml.Statistically significant(P>0.05);the immunoglobulin G synthesis rates of 5 subjects were 26.29±3.79%/w,respectively;The equations are ft=0.16418×(l-e-0.2887t),ft=0.178815x(1-e-0.2241),ft=0.16553×(1-e-0.2951t),ft=0.18560×(1-e-0.2191t),ft=0.17256×(1-e-0.2874t).By comparing the daily dietary status of the subjects with the relevant indicators under the control of dietary status,the results showed that there was no significant difference in protein energy supply ratio and plasma total protein concentration before and after intervention(P>0.05),while lysine intake,Dietary fat and carbohydrate energy supply ratio,plasma lysine concentration,plasma IgG concentration and its synthesis rate were statistically different(P<0.05).This indicates that this controlled lysine intake does not meet the subject’s lysine requirement..ConsultsUnder the control of dietary lysine intake,the actual lysine intake of the subjects was significantly lower than that of the daily dietary lysine intake,and the immunoglobulin G score synthesis rate was also significantly lower than the daily diet.State,indicating that 70mgl(kg·d)can not meet the daily dietary needs of healthy young men.