Discovery of the regulatory role of calcium ion in muscle contraction and relaxation: Setsuro Ebashi and the international emergence of Japanese muscle research

Abstract

Setsuro Ebashi proposed the calcium concept of muscle contraction and relaxation in 1961. It was a very unpopular theory. He showed that Ca2+ activated contraction and that the sarcoplasmic reticulum caused relaxation by binding Ca2+ in an ATP-dependent manner. Most notably, he discovered the receptor that mediated Ca2+ control of contraction and named it “troponin.” Ebashi’s discoveries are considered to be the most important in the muscle field since the 1950s.