Glutamine nitrogen kinetics in insulin-dependent diabetic humans.
To assess the effect of insulin deficiency on whole body glutamine kinetics, five young adults with type I (insulin-dependent) diabetes received 4-h primed continuous infusions of L-[1-13C]leucine and L-[2-15N]glutamine in the postabsorptive state after blood glucose had been clamped overnight at either a normoglycemic level (approximately 85 mg/dl) or a moderate hyperglycemic level (approximately 260 mg/dl) by means of an automated glucose control insulin infusion system. The hyperglycemic state was associated with a significant rise in leucine level [from 165 +/- 23 to 242 +/- 62 (SD) microM], appearance rate (from 125 +/- 11 to 142 +/- 17 mumol.kg-1.h-1), and oxidation (from 27 +/- 10 to 31 +/- 10 mumol.kg-1.h-1). In contrast, neither the plasma level nor the appearance rate of glutamine (333 +/- 51 vs. 318 +/- 58 mumol.kg-1.h-1) was affected. We conclude that insulin deficiency resulting in moderate hyperglycemia induces a 13% rise in whole body proteolysis and yet does not stimulate glutamine de novo synthesis, despite increased precursor availability.
Darmaun
D
D
Institut National de la Santé et de la Recherche Médicale Unité 290, St. Lazare Hospital, Paris, France.
Rongier
M
M
Koziet
J
J
Robert
J J
JJ
D000328:Adult; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism*; D005973:Glutamine / Q000378:metabolism*; D006801:Humans; D006943:Hyperglycemia / Q000378:metabolism; D007328:Insulin / Q000172:deficiency; D007700:Kinetics; D007930:Leucine / Q000378:metabolism; D008297:Male; D009584:Nitrogen / Q000378:metabolism*
D007328:Insulin; D005973:Glutamine; D007930:Leucine; D009584:Nitrogen