A study of the cytochromes of Octopus vulgaris Lam.

The presence of haematin compounds in those animals which have a copper pigment that serves as an oxygen carrier was first observed in 1886 by MacMunn. In 1925, Keilin confirmed MacMunn's observations and found cytochrome in several groups of invertebrates devoid of haemoglobin. In 1940, Ball & Meyerhof, by direct spectroscopic observations, indicated the presence of ironporphyrin compounds in some marine animals whose blood pigment is haemocyanin; they found cytochromes a, b, c and cytochrome oxidase in the heart and some body muscle of molluscs and crustaceans. In 1946, however, Warburg suggested that all those organisms might have also enzymes which are capable of transporting oxygen by means of copper. No further information can be found in the literature, and it is generally accepted that the process of oxygen utilization in molluscs is similar to that in mammals except for the substitution of haemocyanin for haemoglobin as oxygen carrier. This paper brings direct evidence, based upon spectrophotometric and enzymic investigations, for the presence in particles isolated from the body muscle of Octopu vulgaris of a cytochrome system composed of cytochromes a, a3, b and c. This evidence, however, does not exclude the possibility that other systems are operating in the terminal respiration of Octopus.