Protein Constituents of Spermatozoa 



87 



tails. The products thus obtained were extracted with lipid solvents 

 and dried. The lipid-free dry weights of heads, middle-pieces and 

 tails were 51, 16, and 33%, respectively, of the whole spermatozoa. 

 The content of ash, nitrogen, phosphorus, sulphur, cystine, and 

 methionine in the three fractions is shown in Table 11. 



Table 11. Composition of sperm-heads, middle-pieces, and tails, 



dissociated by ultrasonic disintegration of bull spermatozoa 



(Zittle and O'Dell, 1941«) 



* Corresponding to a content of 40-5% deoxyribonucleic acid. 



In the author's experience (Mann, 1949, 19516), a relatively simple 

 procedure for the disruption of ram spermatozoa is to shake them 

 with fine glass beads in the mechanical disintegrator of Mickle 

 (1948). Such treatment leads to fragmentation of the middle-pieces 

 and tails, though not of the sperm-heads, and yields on slow centri- 

 fugation a yellow-coloured, opalescent fluid which probably repre- 

 sents the sperm cytoplasm. This material is very rich in enzymes; it 

 contains among others, the intermediary enzymes of fructolysis, 

 certain phosphatases, and the complete cytochrome-cytochrome 

 oxidase system, as well as a potent succinic dehydrogenase, the 

 activity of which can be demonstrated both by methylene-blue reduc- 

 tion and by oxygen uptake in presence of succinate. The succinic 

 dehydrogenase activity shown by disintegrated ram spermatozoa 

 contrasts strikingly with the behaviour of the fresh intact sperm 

 cells, the O2 consumption of which is not markedly enhanced by the 

 addition of succinate. The difference in enzymic behaviour between 

 the intact and disrupted sperm cells has something of a parallel in 

 the activity of blood carbonic anhydrase which can be demonstrated 

 much more readily in laked than in unlaked, erythrocytes (Keilin 

 and Mann, 1941). 



