CHAPTER VI 



Lipids and their Role in the 

 Metabolism of Semen 



Lipids in spermatozoa. The lipid capsule. Acetal phospholipids or plas- 

 malogens. Role of lipids in sperm metabolism. Lipids in the seminal plasma 

 and male accessory gland secretions. 'Lipid bodies' and prostatic calculi. 



Lipids in spermatozoa 



The first systematic analysis of lipids in spermatozoa was carried 

 out by Miescher (1878, 1897) who also proved that the lipids are 

 concentrated chiefly in the sperm-tails. His analytical results showed 

 that the ether-extractable material obtained from salmon sperma- 

 tozoa is composed of about 50% lecithin, 14% cholesterol and 

 35% fat, and that by far the greatest part of this material is derived 

 from the sperm-tails where lecithin accounts for 31-83%, fats and 

 cholesterol for 26-27%, and protein for the remaining 41 -90% of the 

 organic contents. This led Miescher to conclude that the sperm- 

 tails resemble in their composition the grey matter of the nervous 

 system, and in a letter to W. Hiss he wrote: 'The more I deal with 

 the tails, the more probable it appears to me that we have before 

 us essentially the chemical type of the non-medullated nerves, that 

 is the axis cylmders.' Subsequent investigations by Mathews (1897) 

 and Sano (1922) on the sperm of herring, salmon, porgy and cod- 

 fish, confirmed the presence of lecithin and revealed at the same 

 time the presence of small quantities of certain other lipids, includ- 

 ing cephalin and sphingomyelin. 



H2C — O — CORunsat. 



I 

 HC— O— CORsat. Lecithin 



O 



II 

 H2C— O— P— O— CH2-CH2 



I I 



O- +N(CH3)3 



124 



