Fig. 2

Cordycepin increased protein kinase A (PKA) activity and protein tyrosine phosphorylation during human sperm capacitation. (A) An ELISA-based PKA activity assay kit measured human sperm PKA activity after capacitation for 3 h. The optical density at 450 nm (OD450) was recorded. Data are presented as means ± standard deviation (SD; n = 3). *P < 0.05 (compared with the dimethyl sulfoxide [DMSO] group). (B) Western blotting was used to measure the protein tyrosine phosphorylation of human sperm. (C) The ratio of protein tyrosine phosphorylation levels to that of GAPDH. Data are presented as means ± standard deviation (SD; n = 3). *P < 0.05 (compared with the DMSO group)