This study was undertaken to clarify the effects of electrical stimulation on the biochemical properties of plaice sarcoplasmic reticulum and myofibrils at early period of death. The plaices were electrically stimulated (110V/60 Hz) In sea water bath ...
This study was undertaken to clarify the effects of electrical stimulation on the biochemical properties of plaice sarcoplasmic reticulum and myofibrils at early period of death. The plaices were electrically stimulated (110V/60 Hz) In sea water bath for 15, 35, and 60 seconds, and killed instantly by spiking at the head. Killed samples were investigated for the changes in $Ca^{2+}$-ATPase activity of FSR (fragmented sarcoplasmic reticulum), LSR (light SR), HSR (heavy SR), and SDS-PAGE pattern of FSR. $Ca^{2+}$-ATPase activity of FSR increased until $45^{\circ}C$ and inactivated over $50^{\circ}C$. $Ca^{2+}$-ATPase activity of FSR remarkably decreased according to the duration of electrical stimulation. Myofibrillar $Mg^{2+}$-ATPase activity of electrically stimulated plaices in the presence of $Ca^{2+}$ was higher than that of sample instantly killed by spiking. $Mg^{2+}$-ATPase activity of myofibrils increased by electrical stimulation and the activity decreased during storage at $5^{\circ}C$. Myofibrillar $Mg^{2+}$-ATPase activity in sample killed by spiking was not affected by $Ca^{2+}$ ion. Myofibrillar $Mg^{2+}$-ATPase activity of electrically stimulated sample in the absen-re of $Ca^{2+}$ decreased during storage at $5^{\circ}C$, whit $Mg^{2+}$-ATPase activity in unstimulated sample did not show any change. $Ca^{2+}$-sensitivity of myofibrils showed no differences between electrically stimulated sample and sample killed by spiking, and the was no change during at $5^{\circ}C$.