| Sign In to gain access to subscriptions and/or personal tools. |
Protein Metabolism Assessed by 1-13C Leucine Infusions in Patients Undergoing Bone Marrow TransplantationDivision of Endocrinology and Metabolism, Departments of Medicine and Research, University Hospital, Basel
Division of Endocrinology and Metabolism, Departments of Medicine and Research, University Hospital, Basel
Division of Hematology, Departments of Medicine and Research, University Hospital, Basel
NESTEC Lab, Vers-chez-les-Blanc, Switzerland
Division of Endocrinology and Metabolism, Departments of Medicine and Research, University Hospital, Basel
NESTEC Lab, Vers-chez-les-Blanc, Switzerland
Division of Endocrinology and Metabolism, Departments of Medicine and Research, University Hospital, Basel
Division of Endocrinology and Metabolism, Departments of Medicine and Research, University Hospital, Basel Patients receiving cytoreductive therapy and bone marrow transplantation (BMT) are known to develop marked protein catabolism. To assess the contribution of whole body protein breakdown, amino acid oxidation and incorporation into proteins, plasma leucine kinetics (1-13C-leucine infusion technique) were determined in six patients five times within 14 days before and after cytoreductive therapy (Cyclophosphamide and total body irradiation) and marrow transplantation. Nitrogen balance became negative (—0.20 ± 0.04 g/ Kg/24 hr) after cyclophosphamide (p < 0.01) and was -0.25 ± 0.05 g/Kg/24 hr 7 days after BMT in spite of total parenteral nutrition. Plasma leucine concentration increased after BMT by 67% (p < 0.0015). Leucine plasma appearance was 1.20 ± 0.15 µmol/ kg/min before treatment, it increased slightly and transiently after cyclophosphamide, and increased again from day 5 to day 7 after BMT (p < 0.01), suggesting increased protein breakdown. Leucine oxidation increased from 0.27 ± 0.07 before therapy to 0.97 ± 0.16 µmol/kg/min (p < 0.02) after cyclophosphamide and BMT. Nonoxidative leucine disappearance rate decreased slightly from 0.92 ± 0.08 to 0.75 ± 0.16 µmol/kg/min after BMT (ns). Leucine metabolic clearance rate decreased from 11.8 ± 1.65 before therapy to 6.9 ± 0.70 ml/kg/min (p < 0.02) after cytoreductive therapy. After BMT it increased again to 9.9 ± 1.5 ml/kg/min (p < 0.02). The results demonstrate that patients undergoing cytoreductive therapy and bone marrow transplantation develop negative nitrogen balance due to increased protein breakdown associated with increased leucine oxidation and increased metabolic clearance rate. Leucine incorporation into proteins (protein synthesis) was not altered inspite of an increase in plasma leucine concentration. ( Journal of Parenteral and Enteral Nutrition 14:480-484, 1990)
Journal of Parenteral and Enteral Nutrition, Vol. 14, No. 5,
480-484 (1990) This article has been cited by other articles:
|
|
||||||||||||||||||||||||||||||||||||||||||||||||||


