抄録
1. The efflux and uptake of Ca in Mytilus ABRM at rest and during potassium contracture were examined by use of 45Ca.
2. The Ca efflux during potassium contracture was 0.162 p-mol/cm2. sec. and increased to about 6 times that of the resting state.
3. The resting influx of Ca was 0.028 p-mole/cm2. sec. The increase of Ca uptake during potassium contracture in 2 min was 0.145μ mol/g wet wt. muscle and the Ca influx during the activity was 0.258 p-mol/cm2. sec. Therefore the Ca influx during potassium contracture increased about 9 times that of the resting state.
4. The activation of the contraction of Mytilus ABRM was discussed on the basis of these results and other physiological properties. It was suggested that the initiation of contraction of Mytilus ABRM may be associated with Ca entry from the extracellular space.
