Chem. [f. Gr. σύντονος SYNTONOUS + -IN.] An acid albuminous substance found in muscular tissue, or produced from myosin by the action of acids.
1859. Carpenter, Anim. Phys., i. 33. The substance of which muscles are composed has been commonly considered to be Fibrin, but it differs essentially from fibrin in its properties, and is now distinguished as Syntonin.
1872. Huxley, Physiol., vi. 134. The Syntonin which is the chief constituent of muscle and flesh.
1881. Mivart, Cat, 125. About 15 per cent. of the remaining fourth [of the substance of muscle] is found, after death, to consist of an albuminoid substance called syntonin, or muscle fibrin.
