1 80 The Biochemistry of Semen 



based on Jaffe's reaction, determined the creatine and creatinine 

 content in bull and stallion semen. The mean values which he 

 reported for creatine and creatinine were (mg./lOO ml.), 3 and 12-1 

 in the bull, and 6-2 and 3-7 in the stallion, respectively. In the boar, 

 the apparent creatinine content has been stated to be in blood 

 plasma 2-4, in whole semen 0-3, and in the seminal vesicle secretion 

 5-3 mg./lOO ml. (McKenzie et al., 1938). 



The generally held belief that in invertebrate animals arginine 

 occurs in place of creatine is not supported by results of chemical 

 analyses of gonads and sperm. Greenwald (1946) found in the 

 sperm-laden nephridia of Echiurus 144 mg./lOO g. of apparent crea- 

 tine, and 189 and 270 mg./lOO g. in the testes of Arbacia and 

 Strongylocentrotus, respectively. He succeeded in preparing sub- 

 stantial quantities of pure creatine and creatinine, from the testes 

 and sperm of several invertebrates, including the sea-urchin (Stron- 

 gylocentrotus), Urechis caupo, Holothwia tubiilosa, and Cuciimaria 

 frondosa. In the case of the gonads of two ascidia, Microcosmus 

 sulcatus and Boltenia, which contain chromogenic material, no 

 creatine or creatinine could be isolated but 019 g. of pure betaine 

 picrate was obtained from 150 g. of mixed gonads of Boltenia, 

 indicating a concentration of at least 44 mg. of betaine per 100 g. 

 of tissue. In the testes of arthropods, molluscs, and of a nematode 

 (Ascaris), the amount of chromogenic material was so low as to 

 indicate absence of creatine. 



Phosphocreatine and phosphoarginine 



The possibility that spermatozoa may contain creatine in the 

 form of phosphocreatine was envisaged by Eggleton and Eggleton 

 (1929) who found that the testes contain, next to skeletal muscle, 

 the second largest concentration of phosphagen. Soon after the dis- 

 covery by Parnas, Ostern and Mann (1934o, b) that extracts from 

 skeletal muscles can synthesize phosphocreatine from creatine and 

 phosphopyruvic acid, the same enzymic reaction was investigated 

 in bovine epididymal spermatozoa by Torres (1935) who claimed 

 that bull spermatozoa are definitely capable of such a synthesis. 

 Her claim, however, has been refuted by Ivanov (1937) who failed 

 to detect any synthesis of phosphocreatine in sperm, although he 

 experienced no difficulty in confirming our results on muscles. 



