Spermine, Choline, Ergothioneine 167 



were, prostate 456, pancreas 77, adrenal 58, liver 43, spleen 40, 

 testis 29, ovary 9. It is doubtful if Fuerbringer's (1886) belief in the 

 'vitalizing' effect of the prostatic secretion upon spermatozoa could 

 be applied to spermine as such; Harrison (1931, 1933) was unable to 

 detect any activating influence of spermine phosphate on human 

 spermatozoa. In contrast to human, bull semen contains no sper- 

 mine; this is not surprising in view of the absence of a true functional 

 prostate in the latter species. 



Oxidation of spermine and spermidine by diamine oxidase 



Spermine and spermidine, both undergo oxidation in the presence 

 of diamine oxidase, an enzyme of which there is about a hundred 

 times more in human seminal plasma than in blood serum (Zeller, 

 1941); this finding together with observations by earlier investigators 

 who found that the oxygen uptake of human semen is linked with 

 the seminal plasma rather than the spermatozoa, led Zeller and 

 Joel (1941) to suggest that the oxygen consumption in human semen 

 is mediated chiefly by the spermine-diamine oxidase system. This 

 requires further experimental proof. 



State of spermine in semen 



An interesting but as yet unsolved problem relates to the state 

 of spermine in freshly voided semen. Some investigators envisaged 

 the possibility that spermine occurs already in fresh semen as a 

 phosphate salt which being poorly soluble, separates from the semen 

 in the characteristic shape of Boettcher's crystals. However, in 

 freshly ejaculated human semen there is not enough inorganic 

 phosphate to combine with all the spermine and the content of 

 inorganic phosphate increases on standing owing to the breakdown 

 of phosphorylcholine (see p. 170). Furthermore, it has been the 

 experience of all those who tried to obtain crystalline spermine 

 phosphate from semen, that a successful crystallization can best be 

 achieved with semen which has been allowed to stand for at least a 

 few hours after ejaculation or by following Fuerbringer's recom- 

 mendation and treating it with additional phosphate. Fuerbringer's 

 (1881) interpretation of his own findings was that the basic com- 

 ponent of Boettcher's crystals in ejaculated semen originates in the 



