KINETICS OF DODECANEDIOIC ACID AND EFFECT OF ITS ADMINISTRATION ON GLUCOSE KINETICS IN RATS

Dodecanedioic acid (C12), a saturated aliphatic dicarboxylic acid with twelve C atoms, was given as an intraperitoneal bolus to male Wistar rats, with the aim of evaluating C12 suitability as an energy substrat e for parenteral nutrition. The 24 h urinary excretion of C12 was 3.9% of the administered dose. C12 kinetics were investigated by a one com partment model with saturable tissue uptake and reversible binding to plasma albumin. The analysis of plasma concentration and urinary excre tion data from different animals yielded the population means of the k inetic parameters: renal clearance was 0.72 ml/min per kg body weight (BW) (much smaller than inulin clearance in the rat), and maximal tiss ue uptake was 17.8 mu mol/min per kg BW corresponding to 123.7 J/min p er kg BW. These results encourage the consideration of C12 as a possib le substrate for parenteral nutrition. To investigate the effect of C1 2 administration on glucose kinetics, two other groups of rats, one tr eated with an intraperitoneal bolus of C12 and the other with saline, were subsequently given an intravenous injection of D-[U-C-14]glucose in a tracer amount, Radioactivity data of both control and C12-treated rats were analysed by means of a two compartment kinetic model which takes into account glucose recycling. The estimates of glucose pool si ze (2.3 mmol/kg BW) and total-body rate of disappearance (82.1 mu mol/ min per kg BW) in control rats agreed with published values. In C12-tr eated rats, the rate of disappearance appeared to be reduced to 36.7 m u mol/min per kg BW and the extent of recycling appeared to be negligi ble.