Measurement of whole-body protein turnover in insulin-dependent (type 1) diabetic patients during insulin withdrawal and infusion: comparison of [13C]leucine and [2H5]phenylalanine methodologies.
Clin Sci (Lond)
; 80(4): 345-52, 1991 Apr.
Article
en En
| MEDLINE
| ID: mdl-1851071
ABSTRACT
1. The aims of this study were twofold (i) to investigate the ability of a recently described [2H5]phenylalanine method for quantifying whole-body protein turnover during acute physiological perturbation; (ii) to determine specifically whether the previously observed increase in protein synthesis on insulin withdrawal in insulin-dependent (type 1) diabetic patients seen when employing the [13C]leucine technique could be corroborated by using [2H5]phenylalanine. 2. Whole-body protein turnover was measured by both the [2H5]phenylalanine and [13C]leucine primed continuous infusion methods applied simultaneously to six type I post-absorptive diabetic patients during insulin withdrawal and infusion. 3. Values were determined by the [13C]leucine method by measuring either [13C]leucine (primary pool) or alpha-[13C] ketoisocaproic acid (reciprocal pool) enrichment in plasma. 4. Values of whole-body protein breakdown during insulin withdrawal derived from the [2H5]phenylalanine and primary and reciprocal pool [13C]leucine models respectively were 3.54 +/- 0.43, 3.85 +/- 0.41 and 4.62 +/- 0.44 g day-1 kg-1 (means +/- SD). Insulin infusion resulted in a significant reduction (P less than 0.02) to 3.07 +/- 0.34, 3.05 +/- 0.26 and 3.82 +/- 0.4 g day-1 kg-1, respectively. Synthesis values fell significantly but by a smaller amount than breakdown, resulting in increased (P less than 0.05) net protein deposition, regardless of the model used. 5. These data demonstrate that the [2H5]phenylalanine and [13C]leucine methods generate similar results both in absolute and relative terms in response to short-term insulin infusion. 6. The confirmation of increased whole-body protein synthesis during insulin withdrawal by two independent methods supports the validity of this observation.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Fenilalanina
/
Proteínas
/
Diabetes Mellitus Tipo 1
/
Leucina
Tipo de estudio:
Clinical_trials
Límite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
Clin Sci (Lond)
Año:
1991
Tipo del documento:
Article
País de afiliación:
Reino Unido