Seasonal effects on Ca2+ transport of sarcoplasmic reticulum and on meat quality of pigs with different malignant hyperthermia status

The intracellular Ca2+ concentration is mainly regulated by the sarcoplasmi c reticulum (SR). A disturbed regulation leads to an increased metabolism a nd ultimately to inferior meat quality. In this study, pigs with normal and mutated calcium release channels (referred to as MHR and MHS, respectively ) were used. One batch of pigs was slaughtered in winter months and another in summer months. The intention was to elucidate the impact of season on t he Ca2+ transport of SR and on meat quality in dependence of the MH-status. The results show an impact of MH-status and of season on the meat quality with inferior values in summer months, and in MHS pigs. Immediately after s laughter the rate of Ca2+ sequestration of the SR with biochemically closed and with opened calcium release channels (CRC) was not different between e xperimental groups. However, with basic CRC (not biochemically manipulated) the Ca2+ uptake rate of MHR muscle of summer pigs was significantly reduce d and at the level of that of MHS pigs. The results indicate an impact of s ummer season on the ability of SR to regulate Ca2+ concentration properly e ven in pigs with a normal CRC. This disturbed Ca2+ regulation is correlated with diminished meat quality. (C) 2000 Elsevier Science Ltd. All rights re served.