192 The Biochemistry of Semen 



function of inositol became apparent when Chargaff and his co- 

 workers (1948) reported that in tissue cultures inositol protects 

 dividing fibroblasts from the toxic effect of colchicine and other 

 mitotic poisons. 



It remains for future studies to determine more fully the function 

 of inositol in boar semen. Judging from the author's own experi- 

 ments there is little evidence that inositol is metabolized directly by 

 spermatozoa. One is inclined to assume for inositol a role in the 

 maintenance of the osmotic equilibrium in boar seminal plasma, 

 seeing that the seminal vesicle secretion, unlike other body fluids 

 of the pig, is almost completely devoid of sodium chloride (Mann, 

 1953, 1954). 



Relation to other seminal constituents 



The mechanism by which inositol is formed in mammals is 

 obscure but two tentative hypotheses have been put forward in the 

 past. One involves its formation from a derivative of phosphoinositol 

 such as for instance, lipositol. Fischer (1945) however, believes that 

 inositol acts in the animal body as a sort of chemical intermediary 

 between the sugars and certain aromatic substances, or alternatively, 

 as a reserve carbohydrate for hexoses. The close structural similarity 

 of inositol to glucose as well as to fructose, is certainly a point 

 which must be considered in future investigations on the origin 

 of seminal inositol. 



