The Research Of Daily Lysine Intake On Synthesis Kinetics Of Plasma Proteins In Healthy Young Men

Purpose2H2O was used as a tracer to mark the plasma proteins in healthy young men,to research the effect of daily lysine intake on synthesis kinetics of plasma proteins.We intend to discuss the level of lysine intake is a question whether to affect the synthesis kinetics of albumin or Immunoglobulin G.Methods1.Main nutrient intakes of healthy young men in daily lysine intakeFive healthy young men from Yang Zhou University whose age in 20±1.73 years and BMI in 21.99±1.72kg/m2 was recruited.The body composition tester was used to measure the weight,BMI,rate of muscle and the fat percentage in subjects.The food samples was selected by duplicate portion studied and the contents of lysine,water,protein,fat,ash,carbohydrate and energy were determined trough laboratory detection.2.The synthesis kinetics of albumin was detected by 2H2O in healthy young menHeavy water is used as the indicator to label subjects’ protein in five weeks.The amount of albumin and total protein was detected.And the abundance of 2H-alanine in albumin and the abundance of 2H-alanine in plasma free alanine was detected by GC/MS.The five subjects were respectively drawn diagrams about 2H tracer change trend in albumin,calculating the equation of albumin metabolic kinetics and the subjects of albumin synthesis.3.The synthesis kinetics of Immunoglobulin G was detected by 2H20 in healthy young menThe 2H2O-labeled for the subjects is same with albumin.Before detect the abundance of 2H-alanine in IgG by GC/MS,the amount of albumin was detected.The five subjects were respectively drawn diagrams about 2H tracer change trend in albumin,calculating the equation of albumin metabolic kinetics and the subjects of albumin synthesis.Results:1.Main nutrient intakes of healthy young men in daily lysine intakeThe average body mass index of the subjects(kg/m2)were 22.16±1.99,22.06±1.96,21.80±1.97,21.80±1.68,22.03±1.87,and 22.06± 1.80;the average muscle mass rates(%)were 36.92±2.45 37.28±4.15,38.79±2.43,39.75±1.33,38.96±3.37,and 38.24±3.16;average fat percentages(%)were:24.46±6.89,21.08±6.04,21.14±4.55,21.004±4.85,21.40±6.02,20.48±5.68.There was no significant difference in the body composition of the test subjects(p>0.05).The dietary nutrient intakes of the subjects were:lysine 4.33±1.07 g/d,protein 69.17± 10.74 g/d,fat 34.48±5.53g/d,carbohydrates were 361.25±38.20 g/d,energy was 2253.57±514.90 kcal/d,and the daily lysine intake in subjects is 66.60 mg/kg/d.2.The synthesis kinetics of albumin was detected by 2H2O in healthy young menThere is no significant different in the content of albumin and total protein during the experiments(p>0.05).The rate of serum albumin synthesis of subjects respectively were 42.6%/w,47.1%/w,47.3%/w,51.5%/w,48.8%/w.The kinetic equation of albumin synthesis of the 5 subjects were as follow:the number 1 subject ft=0.1348×(1-e-0.426t),the number 2 subject f t=0.1306×(1-e-0.471t),the number 3 subject ft=0.1354×(1-e-0.473t),the number 4 subject ft=0.1302x(1-e-0.515t),the number 5 subject ft=0.1330x(1-e-0.488t).3.The synthesis kinetics of Immunoglobulin G was detected by 2H2O in healthy young menThere is no significant different in the content of IgG during the experiments(p>0.05).The rate of serum IgG synthesis of subjects respectively were 52.9%,57.6%,58.8%,69.5%,60.0%.The kinetic equation of IgG synthesis of the 5 subjects were as follow:the number 1 subject ft=0.1326×(1-e-0.529t),the number 2 subject ft-0.1285×(1-e-0.576t)，the number 3 subject yt=0.1333×(1-e-0.588t),the number 4 subject ft-0.1270×(1-e-0.695t),the number 5 subject ft=0.1291×(1-e-0.600t).ConsultsThrough the kinetic equation of albumin and IgG synthesis,the increase rates of the abundance of 2H-alanine in plasma albumin and IgG were similar in subjects,and they basically reached steady state in about 20 weeks.It is not have obvious correlations about the daily intake of lysine,fractional synthesiS rate of plasna albumin and rgG,2H-alanine abundance in steady state,and steady state time.Thus,the synthesis kinetics related parameters of plasma albumin and IgG can not be sensitive to reflect the amount of dietary lysine intake in the daily lysine intake state.