Whole body protein kinetics in women: effect of pregnancy and IDDM during anabolic stimulation.
The effects of pregnancy and type 1 diabetes [insulin-dependent diabetes mellitus (IDDM)] on protein metabolism are still uncertain. Therefore, six normal and five IDDM women were studied during and after pregnancy, using [(13)C]leucine and [(2)H(5)]phenylalanine with a hyperinsulinemic-euglycemic clamp and amino acid infusion. Fasting total plasma amino acids were lower in pregnancy in normal but not IDDM women (2,631 +/- 427 vs. 2,057 +/- 471 and 2,523 +/- 430 vs. 2,500 +/- 440 micromol/l, respectively). Whole body protein breakdown (leucine) increased in pregnancy [change in normal (delta N) and IDDM women (delta D) 0.59 +/- 0.40 and 0.48 +/- 0.26 g. kg(-1). day(-1), both P < 0.001], whereas reductions in protein breakdown due to insulin/amino acids (delta N -0.57 +/- 0.19, delta D -0.58 +/- 0.20 g. kg(-1). day(-1), both P < 0.001) were unaffected by pregnancy. Protein breakdown in IDDM women was not higher than normal, and neither pregnancy nor type 1 diabetes altered the insulin sensitivity of amino acid turnover. Nonoxidized leucine disposal (protein synthesis) increased in pregnancy (delta N 0.67 +/- 0.45, delta D 0.64 +/- 0.34 g. kg(-1). day(-1), both P < 0.001). Pregnancy reduced the response of phenylalanine hydroxylation to insulin/amino acids in both groups (delta N -1.14 +/- 0.74, delta D -1. 12 +/- 0.77 g. kg(-1). day(-1), both P < 0.05). These alterations may enable amino acid conservation for protein synthesis and accretion in late pregnancy. Well-controlled type 1 diabetes caused no abnormalities in the regulation of basal or stimulated protein metabolism.
Whittaker
P G
PG
Department of Obstetrics and Gynecology, University of Newcastle upon Tyne, Royal Victoria Infirmary, Newcastle, Tyne and Wear NE1 4LP, United Kingdom. paul.whittaker@erols.com
Lee
C H
CH
Taylor
R
R
D000596:Amino Acids / Q000008:administration & dosage / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D002247:Carbon Isotopes; D003903:Deuterium; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism*; D005260:Female; D015309:Glucose Clamp Technique; D006801:Humans; D006900:Hydroxylation; D007328:Insulin / Q000008:administration & dosage / Q000097:blood; D007700:Kinetics; D007930:Leucine; D010084:Oxidation-Reduction; D010649:Phenylalanine; D011247:Pregnancy; D011254:Pregnancy in Diabetics; D011506:Proteins / Q000378:metabolism*
D000596:Amino Acids; D001786:Blood Glucose; D002247:Carbon Isotopes; D007328:Insulin; D011506:Proteins; D010649:Phenylalanine; D003903:Deuterium; D007930:Leucine