Whole body protein kinetics in women: effect of pregnancy and IDDM during anabolic stimulation

Am J Physiol Endocrinol Metab. 2000 Nov;279(5):E978-88. doi: 10.1152/ajpendo.2000.279.5.E978.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids / administration & dosage
  • Amino Acids / blood
  • Blood Glucose / metabolism
  • Carbon Isotopes
  • Deuterium
  • Diabetes Mellitus, Type 1 / metabolism*
  • Female
  • Glucose Clamp Technique
  • Humans
  • Hydroxylation
  • Insulin / administration & dosage
  • Insulin / blood
  • Kinetics
  • Leucine
  • Oxidation-Reduction
  • Phenylalanine
  • Pregnancy
  • Pregnancy in Diabetics*
  • Proteins / metabolism*

Substances

  • Amino Acids
  • Blood Glucose
  • Carbon Isotopes
  • Insulin
  • Proteins
  • Phenylalanine
  • Deuterium
  • Leucine