Effect of dantrolene treatment on muscle metabolism and meat quality of anesthetized pigs of different halothane genotypes.

Muscle metabolism was studied in pigs of different halothane genotypes by taking blood and muscle biopsy samples during a 45-min preslaughter period of anesthesia. Dantrolene was administered to half the pigs of each genotype to investigate whether possible differences in muscle metabolism could be explained by differences in resting myoplasmic calcium concentrations. Dantrolene influenced muscle metabolism of all halothane genotypes to the same extent, leading to higher (P < .05) glycogen and creatine phosphate concentrations and lower (P < .05) lactate and creatine concentrations. Dantrolene could not reduce the small but significant (P < .05) differences observed in resting muscle metabolism between the genotypes, and halothane-positive pigs had lower (P < .05) glycogen and creatine phosphate contents. Postmortem muscle metabolism showed differences (P < .05) between the three halothane genotypes, with the highest rate of glycolysis in halothane-positive pigs. Dantrolene resulted in a significantly slower (P < .05) glycogen and creatine-P breakdown, which led to a less rapid (P < .05) accumulation of lactate and creatine in both muscles. Meat quality characteristics differed between the halothane genotypes but no PSE meat was detected. Dantrolene administration resulted in an elevation (P < .05) of the pH in the longissimus lumborum and in lower (P < .05) rigor values of the semimembranosus, both measured at 45 min after slaughter. Water-holding capacity was higher (P < .05) and Hunter L*-values lower (P < .05) is dantrolene-treated pigs than in the control animals.(ABSTRACT TRUNCATED AT 250 WORDS)