Quantitative Studies of Carnosine and An- Serine in Mammalian Muscle* Ii. the Distribution of Carnosine and Anserine in Various Muscles of Different Species

For comparative purposes, a knowledge of the distribution of carnosine and anserine in various muscles of an animal, and in the muscles of different members of the species, is of interest. The results of several investigators may be compared with respect to the amount of carnosine found by analysis in various muscles of the cat, but the published data are far from consistent. This is all the more surprising in view of the fact that each determined carnosine by slight modifications of the Koessler and Hanke (7) calorimetric diazo method. In an early paper, Hunter (5) reported that he found a variable amount of carnosine in different samples of skeletal muscle from animals of the same species, although he did not study discrete muscles. Mitsuda (9) studied the carnosine content of individual muscles of normal and decerebrate cats, and found a variation in the amount of carnosine, both from muscle to muscle, and from animal to animal. He reported values ranging from 341 to 1799 mg. per 100 gm. of muscle, figures which were far higher than Hunter’s. An error or misprint in Mitsuda’s paper suggests that his carnosine standard may have contained only one-tenth as much carnosine as he stated, in which case his published results would be 10 times too high. Hunter (6) subsequently made a detailed study of the distribution of carnosine in a number of muscles of the cat, and reported