title: Effects of amino acids on glucose disposal.
abstract: Free fatty acids are known to inhibit carbohydrate disposal and oxidation. This action may play an important role in the pathophysiology of insulin resistance and non-insulin-dependent diabetes mellitus. To investigate whether amino acids (AAs) have similar actions, we determined the effects of an intravenously infused mixture of 15 AAs on carbohydrate disposal during euglycemic-hyperinsulinemic clamps associated with either basal or high glucagon concentrations in healthy male volunteers. Plasma glucose concentration was clamped at approximately 4.7 mM (coefficient of variation 4.7%). Insulin infusion (7.18 pmol.kg-1.min-1) raised serum insulin concentrations from 36-50 pM to between 300 and 600 pM. AA infusions (0.5 g.kg-1.h-1.4 h) raised plasma alpha-amino N2 concentrations about five- to six-fold. Infusion of AAs, somatostatin (somatotropin release inhibitory factor, SRIF), and high-glucagon replacement (3.0 ng.kg-1.min-1) reduced the rate of exogenous glucose infusion needed to maintain euglycemia from 51.1 +/- 7.2 mumol.kg-1.min-1 (saline + SRIF + high glucagon) to 28.3 +/- 11.1 mumol.kg-1.min-1 and stimulated endogenous glucose production (from 0 to approximately 17 mumol.kg-1.min-1). Thus, glucose disposal (exogenous infusion plus endogenous production of glucose) remained essentially unchanged. During infusion of AAs + SRIF + basal glucagon replacement (0.25 ng.kg-1.min-1), endogenous glucose production remained completely suppressed, and the rates of exogenous glucose infusion did not change (compared with saline + SRIF + basal glucagon replacement). The data showed that 1) hyperaminoacidemia associated with hyperglucagonemia stimulated endogenous glucose production despite hyperinsulinemia, and 2) intravenous infusion of a mixture of 15 AAs had no inhibitory effect on insulin-stimulated total-body glucose disposal.
authors.affiliation: Department of Medicine, Temple University School of Medicine, Philadelphia, PA.
authors.forename: G
authors.initials: G
authors.lastname: Boden
authors.forename: L
authors.initials: L
authors.lastname: Tappy
mesh_terms: D000328:Adult; D000596:Amino Acids / Q000008:administration & dosage / Q000494:pharmacology*; D001481:Basal Metabolism; D001786:Blood Glucose / Q000378:metabolism; D050260:Carbohydrate Metabolism; D005934:Glucagon / Q000097:blood*; D005947:Glucose / Q000008:administration & dosage / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D007262:Infusions, Intravenous; D007328:Insulin / Q000097:blood / Q000494:pharmacology; D008297:Male; D010084:Oxidation-Reduction / Q000187:drug effects; D013004:Somatostatin / Q000097:blood
chemical_list: D000596:Amino Acids; D001786:Blood Glucose; D007328:Insulin; D013004:Somatostatin; D005934:Glucagon; D005947:Glucose