Treatment of human spermatozoa with follicular fluid can influence lipid content and motility during in vitro capacitation.

In order to evaluate the role of human follicular fluid (HFF) on the fertilizing capacity of spermatozoa, we studied the effect of HFF on the lipid composition and on the movement characteristics of human spermatozoa. Spermatozoa (spz) from normospermic patients were prepared with a discontinuous Percoll gradient and incubated in Ménézo B2 medium with or without a supplement of 20% HFF (HFF-Percoll spz and B2-Percoll spz respectively) for 2 and 24 h. After 2 h HFF incubation, percentage progressive motility, straight line velocity (VSL), and amplitude of lateral head displacement (ALH) were improved in HFF-Percoll spz as compared to B2-Percoll spz (P < or = 0.05). After a longer incubation period (24 h), lipid changes appeared in HFF-Percoll spz with lower levels of cholesterol (P = 0.02) and phospholipids (P = 0.05). No modification of the cholesterol/phospholipid ratio after 2 and 24 h of incubation in either B2-Percoll spz or HFF-Percoll spz was observed. Such decreases in lipid content of HFF-Percoll spz may be factors which could be taken into account as constituting part of membrane modifications during the capacitation process.