The presence of creatine in the testes of various invertebrates; the preparation of creatine phosphoric acid from fish testes.

According to Kutscher and Ackermann (l-3), there is a very marked difference between vertebrate and invertebrate animals in that the latter do not contain creatine, but, in its place, arginine. After t,he discovery of creatine phosphoric acid by Fiske a,nd Subbarow (4,5) and by Eggleton and Eggleton (B), it became of interest to see whether arginine in invertebrate muscle was similarly present in combination with phosphoric acid. This XTas shown to be the cqse for the muscle of crawfish by Meyerhof and Lohmann (7), and for those of Octopus by Lohmann (8). Indirect evidence, chiefly that of the rate of hydrolysis of organic phosphoric acid and the effect thereon of the presence of molybdate ions, has indicated the presence of arginine phosphoric acid in the muscles of other invertebrate forms, including other mollusks and arthropods, platyhelminths, nemertines, annelids, podaxonia, and echinoderms (9-13). It seemed to be of interest to determine whether the forms that are generally believed to be intermediate between the achordates and the true vertebrates contained creatine. Accordingly, in 1929, analyses were made of the muscles of an ascidian, Boltenia, which is found near the Mount Desert Island Biological Laboratory. The teased muscle fibrils of the basket contained a substance which, after heating with acid, reacted with alkaline picrate solution with the production of an orange color. The int,ensity of this reaction indicated an apparent concentration of from 25 to 42 mg. of creatine per 100 gm. of tissue (Table I). Neither the facilities nor the material available permitted further attempt at identification. The conspicuous mixed gonads of Boltenia were found to contain from 36 to 92 mg. of apparent creatine per 100 gm. of tissue. Without heating, the same acid extracts seemed to contain 12 to 25 mg. of apparent creatine per 100 gm. of tissue. About 150 gm. of gonads were collected, preserved by heating in water, and brought to New York for an attempt at isolation of the creatine as potassium creatinine picrate. This was unsuccessful. In the course of this attempt, 0.190 gm. of betaine picratewes obtained, indicating a concent,ration of at least 44 mg. of betaine per 100 gm. of tissue.