Use of Even‐Numbered Carbon Atom Dicarboxylic Salts in Parenteral Nutrition as Fuel Substrate

Abstract

Sebacic acid (C10), a saturated, straight-chain dicarboxylic acid with 10 carbon atoms in disodic salt form, was given intravenously to two groups of healthy male volunteers in order to evaluate its possible use in total parenteral nutrition. The first group, composed of six subjects, received 1000 mg of sebacate as a bolus; six other subjects (second group) received 10 g of sebacate dissolved in 500 mL of double-distilled water at an infusion rate of 3.33 g/h over 3 hours. The serum sebacate data for each subject were analyzed by computer, using biexponential fit corresponding to a 2-compartment open model. The distribution half-life (t_½) was 0.34 ± 0.06 hour and the elimination phase was rather rapid (Ke = 2.10 ± 0.38/h); the volume of the central compartment was 2.79 ± 0.54 L and the volume of tissue compartment 3.72 ± 0.14 L. These data showed a good tissue fixation of sebacate. The plasma clearance was evaluated to be 5.96 ± 2.19 L/h and the renal clearance was 19.22 ± 10.69 L/h, indicating that a tubular secretion of C10 takes place. The serum concentration of sebacate raised to the maximal value at the end of the infusion (180 minutes), corresponded to 480.50 ± 43.02 μg/mL. Respiratory and metabolic parameters were evaluated by indirect calorimetry from the beginning of the infusion for 210 minutes. The O₂ consumption (VO₂ mL/min per square meter) remained essentially unchanged throughout the experiment (from 154.3 ± 28.3 at time 0 to 155.3 ± 39.5 at time 180 minutes). The CO₂ production (VCO₂ mL/min per square meter) decreased from below basal values (147.7 ± 27.3) to 123.7 ± 25.0 at the end of the infusion. Thus, respiratory quotient (RQ) decreased significantly (from 0.96 ± 0.04 to 0.81 ± 0.06) and the percentage of calories derived from lipids increased during and after the infusion (from -0.13 ± 13.3 to 52.1 ± 26.2). Metabolic rate (MR, kcal/h per square meter) remained constant during the entire study period. In conclusion sebacate seems to be a valuable new substrate for use in total parenteral nutrition and may have properties useful in special metabolic conditions. In this study, the urinary excretion of C10 and its products of β-oxidation (suberic [C8] and adipic [C6] acids) was found to be low (totaling less than 16% of the administered dose) and the energy production high (6.64 kcal/g) with C10 being completely oxidized in the organism to CO₂ and H₂O. (Journal of Parenteral and Enteral Nutrition16:32-38, 1992)