抄録
We found that frog skeletal and cardiac muscles can survive for a long period in crude chicken egg white (CEW) . Any extra salts or solvents were not added to CEW. Resting potentials (RP) of skeletal muscle fibers immersed in CEW reduced to about -40 mV. This may be owing to high K+ of CEW. By return from CEW to normal Ringer's solution (NR), the fibers slowly but steadily recovered normal RP and soon conducted normal action potentials (AP). Hind leg amputated at the ankle and dissected whole heart were treated with CEW for a period of 18 days at 1–3 °C. Fibers of toe muscles isolated from the above hind leg were almost intact at a glance. After a day or two, their RP and heights of AP measured in NR at 15–17 °C were -95 ± 2.2 mV and 123 ± 4.5 mV (n = 50, mean±SD), respectively. Similarly, those of cells of ventricle isolated from the above heart were -92 ± 4.9 mV and 122 ± 9.4 mV (n = 46), respectively. The remaining atrium automatically beat about 20 times every min as if it had beaten in situ. Interestingly, some semitendinosus muscles treated with CEW for 3–12 days did not move an inch during twitches but developed almost normal caffeine contractures. Mechanism of this inhibition of E-C coupling is unclear, but such an inhibition was not observed in muscles treated with 190 K+ solution or 5% albumin NR (250 mOsm). Long-term survival of the muscles in CEW may be due to environmental conditions of (1) high viscosity, (2) low temperature, and (3) mild depolarization which act to minimize energy consumption of muscles. [J Physiol Sci. 2007;57 Suppl:S97]
