EFFETTI DEL'INSULINA E DEGLI AMINOACIDI SULL'ANABOLISMO PROTEICO POST-PRANDIALE

Translated title of the contribution: Effects of insulin and amino acids on post-prandial protein anabolism

Elena Volpi, P. Lucidi

Research output: Contribution to journalArticle

Abstract

In type 1 diabetes mellitus, insulin deficiency leads to a loss of protein mass, due to increased protein breakdown and lack of an adequate increase in protein synthesis. Protein anabolism takes place only in the absorptive period. Among hormones and nutrients, insulin and amino acids play a key role in its regulation, but their relative contribution has not been established yet. Thus, we studied 15 healthy subjects, divided in 3 groups. The rates of whole body protein kinetics, and the fractional secretory rates (FSR) of albumin, fibrinogen, antithrombin III (ATIII), and immunoglobulins G (IgG) were measured, during L-[1-14C]leucine infusion, in the post-absorptive period, and during the intragastric (i.g.) infusion of water (Control n = 5), a liquid mixed meal (Meal + AA n = 5), or during the i.g. infusion of an isocaloric meal without amino acids (Meal - AA n = 5) that induced the same insulin response of the Meal + AA. The results of the present study indicate that post-prandial protein anabolism is mainly sustained (90%) by dietary amino acids (leucine balance: Meal + AA 0.77 ± 0.18, Meal - AA -0.20 ± 0.04, Control -0.30 ± 0.03, μmol·kg-1·min-1, p < 0.01 Meal + AA vs Control and Meal - AA). The mechanism responsible for prandial anabolism includes both an increase in whole body protein synthesis (Meal + AA 2.48 ± 0.15, Meal - AA 1.93 ± 0.13, Control 1.73 ± 0.14, μmol·kg-1·min-1, p < 0.01 Meal + AA vs Control and Meal - AA), and a decrease in whole body proteolysis (Meal + AA 1.71 ± 0.26, Meal - AA 2.13 ± 0.16, Control 2.02 ± 0.12, μmol·kg-1·min-1, p < 0.01 Meal + AA vs Control and Meal - AA). The absorption of the isocaloric glucose-lipid meal slightly reduced protein catabolism decreasing amino acid oxidation (Meal - AA 0.20 ± 0.04 vs Control 0.30 ± 0.03, μmol·kg-1·min-1, p = 0.06) and promoting the synthesis of selected proteins (albumin +20% vs Control, p < 0.05), because of the effect of prandial hyperinsulinaemia. The combined action of insulin and amino acids during the absorption of the mixed meal additionally increased albumin FSR (+50% vs Control, p < 0.01, p < 0.03 vs Meal - AA). IgG synthesis was stimulated only by increased amino acid availability (+40%, p < 0.01 vs Control and Meal - AA). Fibrinogen and ATIII FSR did not change during either meal absorption. In conclusion, these data indicate that, during meal absorption in type 1 diabetic patients, appropriate insulinization is required to promote adequate protein anabolism.

Original languageItalian
Pages (from-to)205-216
Number of pages12
JournalGiornale Italiano di Diabetologia
Volume15
Issue number3
StatePublished - 1995
Externally publishedYes

Fingerprint

Meals
Insulin
Amino Acids
Proteins
Secretory Rate
Albumins
Antithrombin III
Leucine
Fibrinogen
Immunoglobulin G

Keywords

  • amino acids
  • insulin
  • leucine kinetics
  • meal
  • protein synthesis

ASJC Scopus subject areas

  • Endocrinology
  • Endocrinology, Diabetes and Metabolism
  • Internal Medicine

Cite this

EFFETTI DEL'INSULINA E DEGLI AMINOACIDI SULL'ANABOLISMO PROTEICO POST-PRANDIALE. / Volpi, Elena; Lucidi, P.

In: Giornale Italiano di Diabetologia, Vol. 15, No. 3, 1995, p. 205-216.

Research output: Contribution to journalArticle

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abstract = "In type 1 diabetes mellitus, insulin deficiency leads to a loss of protein mass, due to increased protein breakdown and lack of an adequate increase in protein synthesis. Protein anabolism takes place only in the absorptive period. Among hormones and nutrients, insulin and amino acids play a key role in its regulation, but their relative contribution has not been established yet. Thus, we studied 15 healthy subjects, divided in 3 groups. The rates of whole body protein kinetics, and the fractional secretory rates (FSR) of albumin, fibrinogen, antithrombin III (ATIII), and immunoglobulins G (IgG) were measured, during L-[1-14C]leucine infusion, in the post-absorptive period, and during the intragastric (i.g.) infusion of water (Control n = 5), a liquid mixed meal (Meal + AA n = 5), or during the i.g. infusion of an isocaloric meal without amino acids (Meal - AA n = 5) that induced the same insulin response of the Meal + AA. The results of the present study indicate that post-prandial protein anabolism is mainly sustained (90{\%}) by dietary amino acids (leucine balance: Meal + AA 0.77 ± 0.18, Meal - AA -0.20 ± 0.04, Control -0.30 ± 0.03, μmol·kg-1·min-1, p < 0.01 Meal + AA vs Control and Meal - AA). The mechanism responsible for prandial anabolism includes both an increase in whole body protein synthesis (Meal + AA 2.48 ± 0.15, Meal - AA 1.93 ± 0.13, Control 1.73 ± 0.14, μmol·kg-1·min-1, p < 0.01 Meal + AA vs Control and Meal - AA), and a decrease in whole body proteolysis (Meal + AA 1.71 ± 0.26, Meal - AA 2.13 ± 0.16, Control 2.02 ± 0.12, μmol·kg-1·min-1, p < 0.01 Meal + AA vs Control and Meal - AA). The absorption of the isocaloric glucose-lipid meal slightly reduced protein catabolism decreasing amino acid oxidation (Meal - AA 0.20 ± 0.04 vs Control 0.30 ± 0.03, μmol·kg-1·min-1, p = 0.06) and promoting the synthesis of selected proteins (albumin +20{\%} vs Control, p < 0.05), because of the effect of prandial hyperinsulinaemia. The combined action of insulin and amino acids during the absorption of the mixed meal additionally increased albumin FSR (+50{\%} vs Control, p < 0.01, p < 0.03 vs Meal - AA). IgG synthesis was stimulated only by increased amino acid availability (+40{\%}, p < 0.01 vs Control and Meal - AA). Fibrinogen and ATIII FSR did not change during either meal absorption. In conclusion, these data indicate that, during meal absorption in type 1 diabetic patients, appropriate insulinization is required to promote adequate protein anabolism.",
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AU - Lucidi, P.

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N2 - In type 1 diabetes mellitus, insulin deficiency leads to a loss of protein mass, due to increased protein breakdown and lack of an adequate increase in protein synthesis. Protein anabolism takes place only in the absorptive period. Among hormones and nutrients, insulin and amino acids play a key role in its regulation, but their relative contribution has not been established yet. Thus, we studied 15 healthy subjects, divided in 3 groups. The rates of whole body protein kinetics, and the fractional secretory rates (FSR) of albumin, fibrinogen, antithrombin III (ATIII), and immunoglobulins G (IgG) were measured, during L-[1-14C]leucine infusion, in the post-absorptive period, and during the intragastric (i.g.) infusion of water (Control n = 5), a liquid mixed meal (Meal + AA n = 5), or during the i.g. infusion of an isocaloric meal without amino acids (Meal - AA n = 5) that induced the same insulin response of the Meal + AA. The results of the present study indicate that post-prandial protein anabolism is mainly sustained (90%) by dietary amino acids (leucine balance: Meal + AA 0.77 ± 0.18, Meal - AA -0.20 ± 0.04, Control -0.30 ± 0.03, μmol·kg-1·min-1, p < 0.01 Meal + AA vs Control and Meal - AA). The mechanism responsible for prandial anabolism includes both an increase in whole body protein synthesis (Meal + AA 2.48 ± 0.15, Meal - AA 1.93 ± 0.13, Control 1.73 ± 0.14, μmol·kg-1·min-1, p < 0.01 Meal + AA vs Control and Meal - AA), and a decrease in whole body proteolysis (Meal + AA 1.71 ± 0.26, Meal - AA 2.13 ± 0.16, Control 2.02 ± 0.12, μmol·kg-1·min-1, p < 0.01 Meal + AA vs Control and Meal - AA). The absorption of the isocaloric glucose-lipid meal slightly reduced protein catabolism decreasing amino acid oxidation (Meal - AA 0.20 ± 0.04 vs Control 0.30 ± 0.03, μmol·kg-1·min-1, p = 0.06) and promoting the synthesis of selected proteins (albumin +20% vs Control, p < 0.05), because of the effect of prandial hyperinsulinaemia. The combined action of insulin and amino acids during the absorption of the mixed meal additionally increased albumin FSR (+50% vs Control, p < 0.01, p < 0.03 vs Meal - AA). IgG synthesis was stimulated only by increased amino acid availability (+40%, p < 0.01 vs Control and Meal - AA). Fibrinogen and ATIII FSR did not change during either meal absorption. In conclusion, these data indicate that, during meal absorption in type 1 diabetic patients, appropriate insulinization is required to promote adequate protein anabolism.

AB - In type 1 diabetes mellitus, insulin deficiency leads to a loss of protein mass, due to increased protein breakdown and lack of an adequate increase in protein synthesis. Protein anabolism takes place only in the absorptive period. Among hormones and nutrients, insulin and amino acids play a key role in its regulation, but their relative contribution has not been established yet. Thus, we studied 15 healthy subjects, divided in 3 groups. The rates of whole body protein kinetics, and the fractional secretory rates (FSR) of albumin, fibrinogen, antithrombin III (ATIII), and immunoglobulins G (IgG) were measured, during L-[1-14C]leucine infusion, in the post-absorptive period, and during the intragastric (i.g.) infusion of water (Control n = 5), a liquid mixed meal (Meal + AA n = 5), or during the i.g. infusion of an isocaloric meal without amino acids (Meal - AA n = 5) that induced the same insulin response of the Meal + AA. The results of the present study indicate that post-prandial protein anabolism is mainly sustained (90%) by dietary amino acids (leucine balance: Meal + AA 0.77 ± 0.18, Meal - AA -0.20 ± 0.04, Control -0.30 ± 0.03, μmol·kg-1·min-1, p < 0.01 Meal + AA vs Control and Meal - AA). The mechanism responsible for prandial anabolism includes both an increase in whole body protein synthesis (Meal + AA 2.48 ± 0.15, Meal - AA 1.93 ± 0.13, Control 1.73 ± 0.14, μmol·kg-1·min-1, p < 0.01 Meal + AA vs Control and Meal - AA), and a decrease in whole body proteolysis (Meal + AA 1.71 ± 0.26, Meal - AA 2.13 ± 0.16, Control 2.02 ± 0.12, μmol·kg-1·min-1, p < 0.01 Meal + AA vs Control and Meal - AA). The absorption of the isocaloric glucose-lipid meal slightly reduced protein catabolism decreasing amino acid oxidation (Meal - AA 0.20 ± 0.04 vs Control 0.30 ± 0.03, μmol·kg-1·min-1, p = 0.06) and promoting the synthesis of selected proteins (albumin +20% vs Control, p < 0.05), because of the effect of prandial hyperinsulinaemia. The combined action of insulin and amino acids during the absorption of the mixed meal additionally increased albumin FSR (+50% vs Control, p < 0.01, p < 0.03 vs Meal - AA). IgG synthesis was stimulated only by increased amino acid availability (+40%, p < 0.01 vs Control and Meal - AA). Fibrinogen and ATIII FSR did not change during either meal absorption. In conclusion, these data indicate that, during meal absorption in type 1 diabetic patients, appropriate insulinization is required to promote adequate protein anabolism.

KW - amino acids

KW - insulin

KW - leucine kinetics

KW - meal

KW - protein synthesis

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