Phospholipids in Mammalian Semen

The earliest investigations on the lipids of spermatozoa are those of Miescher (1878) who reported that the ether-extractable material in the spermatozoa of bull and salmon was about 50 % lecithin. At that time, of course, the term lecithin had no precise chemical connotation. However, a high concentration of phospholipid was subsequently shown to be a general characteristic of spermatozoa where it is present mainly in the mid-pieces and tails. The first inquiries into possible metabolic roles for the phospholipids of spermatozoa were made by Lardy & Phillips (1941 a, b). These authors compared the motility of bull spermatozoa in whole semen with that of spermatozoa which had been separated from the seminal plasma and resuspended in Ringer's solution. Redenz had already shown in 1933 that the motility of bull spermatozoa in whole semen is actively maintained under both aerobic and anaerobic conditions. This is possible because in whole semen