Carbohydrate and lipid metabolism at rest and under physical and metabolic load in normal pigs and those with the genetic mutation for malignant hyperthermia

Abstract

AbstractThe plasma concentrations of glucose, insulin, lactate, cortisol and free fatty acids were investigated in normal pigs and those with the homozygous and heterozygous genetic mutation for malignant hyperthermia (MH). Blood samples were obtained during a 24-h resting period, a glucose tolerance test and during a treadmill test with submaximal physical load conditions. The homozygous MH positive animals elicited the highest glucose concentrations and the homozygous MH negative animals the lowest at each sampling time during the 24-h period (P < 0·01). During the glucose tolerance test, the most pronounced post-prandial increase and the highest plasma concentrations of glucose were found for the homozygous MH positive animals (P < 0·01), which was associated with a late release of insulin. Increasing work loads during the treadmill test run resulted in an increase of plasma cortisol concentrations in all animals (P < 0·01), with the more pronounced increase for the homozygous and heterozygous MH positive animals. Plasma free fatty acid concentrations during the treadmill test differed between the genotypes (P < 0·05). A pronounced increase was found for the homozygous and heterozygous MH positive animals, whereas the MH negative animals provided very constant free fatty acid values, at a low level, independent of the work load. These results indicate that the genetic mutation for MH in pigs affects the metabolic pathways of the energy metabolism, resulting in higher plasma glucose concentrations at rest and higher lipolytic activities under physical load conditions.