DELAYED EXAMPLE IN RIGOR-MORTIS OF SPINAL-CORD DESTROYED PLAICE DETECTED BY MEASUREMENTS OF ISOTONIC CONTRACTION AND ISOMETRIC TENSION

In spinal cord destroyed plaice, two types of ATP degradation pattern were observed. The delay type in rigor of spinal cord destroyed plaice showed slow development of rigor contraction along with an early rapi d decrease of ATP concentration, and fast development of rigor contrac tion along with a slight decrease of ATP concentration near the ultima te ATP/IMP ratio. The initial ATP/IMP ratio was higher and the decreas e of the ratio was slower. In addition, the ATP/IMP ratio at the infle ction point between slow and fast rigor developments was rather higher . As a result, the rigor development in contraction and tension was de layed. The acceleration type commenced strong rigor contraction when t he ATP/IMP ratio was still high. This rigor mortis developed together with tetanus (i.e. rapid ATP degradation by the leak of calcium ions). The onset of rigor mortis was early and its development was rapid. Si nce the acceleration type fish transmitted the strong impulse of spina l cord destruction to the sarcoplasmic reticulum some time after death , the leak of calcium ions occurred some time after death. The acceler ation type was similar to the stressed fish in the fast attainment of rigor contraction, but the onset of rigor contraction was 2h later in the acceleration type than in the stressed fish. Since the stressed fi sh died with excessive exercise applied forcibly, the leak of calcium ions occurred at 2h after death.