The use of in vivo magnetic resonance imaging and spectroscopy to study porcine stress syndrome in young, halothane-susceptible pigs: Preliminary results

<sup>13</sup>C nuclear magnetic resonance spectroscopy – a non-invasive <i>in vivo</i> method to measure muscle glycogen metabolism in pigs of different genotypes

“…Previous in vivo 31 P NMR studies established that especially homozygous stress susceptible pigs (RyR1 = nn) respond to muscle stressors (like for example halothane) with faster phosphocreatine (PCr) decay, faster declining pH level (indicating a higher glycogen depletion), and a simultaneous increase of inorganic phosphate (Pi) combined with an increased adenosine triphosphate (ATP) depletion. Controversial inferences were made for the metabolism at rest and metabolic response of heterozygous pigs (Nn) in comparison with the normal (NN) and homozygous stress susceptible genotype (nn), which were mainly caused by confounding RYR1*line effects (GEERS et al 1992a(GEERS et al ,b, 1996JANZEN et al 1994;SCHOLZ et al, 1995;KOHN, 1997;SCHOLZ, 2002). The purpose of this 13 C NMR spectroscopy study was to test in vivo and to some extent post mortem whether the muscle metabolites (glycogen, creatine) monitored continuously and non-invasively during halothane exposure, would provide more basic knowledge for the effects of single or multiple gene polymorphisms like the ryanodine receptor 1 mutation or the Hampshire gene effect (RNor PRKAG3).…”