Phospholipids in guinea pig spermatozoa before and after capacitation in vitro

Phospholipids of guinea pigs spermatozoa were examined using high performance liquid chromatography (HPLC) and thin layer chromatography (TLC). Two types of spermatozoa were compared: fresh epididymal (uncapacitated) spermatozoa and epididymal spermatozoa preincubated in Ca2+-free medium for 17-18 hr (capacitated spermatozoa). Determination of lipid phosphorus revealed that the total phospholipid content of spermatozoa did not change significantly during capacitation of spermatozoa. HPLC analyses of choline and ethanolamine phosphatides, lysophosphatides, and sphingomyelin revealed that the relative amounts of these phospholipids remained unchanged during capacitation. In contrast to spermatozoa, phospholipids in the medium surrounding spermatozoa reduced by 20% during capacitation of spermatozoa, suggesting that spermatozoa may utilize extracellular phospholipids as possible energy sources during their capacitation.