Fig. 3. (A) Time-dependent effect of LY294002 on intracellular cAMP levels in swim-up-selected human spermatozoa. After different times of incubation with LY294002 (10 µM), sperm samples were washed and extracted in ethanol. Intracellular cAMP concentrations were evaluated by a RIA kit as described in Materials and Methods. Data represent means±s.e.m. from eight different experiments. ^*P<0.01, ^**P<0.001 versus control. Student's t-test for paired data. (B) Effects of dbcAMP and LY294002 on sperm motility. Swim-up-selected sperm samples were incubated for 1 hour in the presence of dbcAMP (1 mM) or LY294002 (10 µM) alone or in combination and forward and rapid motility was evaluated by CASA. Data represent means±s.e.m. from five different experiments. The percentage of sperm forward motility for swim-up-selected spermatozoa is indicated on the left ordinate, whereas the right ordinate indicates the same parameter for unselected spermatozoa. ^*P<0.001 versus respective controls, Student's t-test for paired data.