Small-angle X-ray diffraction studies of a molluscan smooth muscle in the catch state.
Small-angle X-ray diffraction patterns from the anterior byssus retractor muscle of Mytilus edulis in the resting, active, and catch states were examined closely to elucidate the structural features of catch. The specimens were isometrically contracted by stimulation with acetylcholine. The specimens that produced strong tensions in both the active and catch states showed noticeable structural change in the thick filaments. Although the tension was weaker in the catch state than in the active state, the axial spacings of the 14.5 nm meridional reflection and its higher order reflections from the thick filaments were more elongated in the catch state than in the active state. This means that the thick filaments were stretched more strongly in the catch state than in the active state.
Tajima
Yoshiko
Y
Department of Physics, Tokyo Metropolitan University, 1-1 Minami-Ohsawa, Hachioji, Tokyo 192-0397, Japan. ytajima@basil.ocn.ne.jp
Takahashi
Wataru
W
Ito
Akihiko
A
D000818:Animals; D018485:Muscle Fibers, Skeletal / Q000502:physiology*; D009130:Muscle, Smooth / Q000502:physiology*; D049880:Mytilus edulis / Q000502:physiology*; D014961:X-Ray Diffraction