Sperm function and production of bovine embryos in vitro after swim-up with different calcium and caffeine concentration

Frozen semen from hulls was used in artificial insemination programs was su bmitted to swim-up in Sperm Talp media containing different calcium (1.8, 2 .6, 3.6 mM) or caffeine (2.5, 5.0, 7.5 muM) concentrations. The following s perm variables were evaluated: sperm recovery, motility, vigor, morphology, alterations in the pattern of capacitation by chlortetracycline (CTC) stai ning, and alterations in lysophosphatidyl choline (LPC)-induced acrosome re action (AR). Sperm obtained from swim-up under different conditions were al so tested for in vitro embryo production. No significant differences in the variables motility, vigor. morphology, and LPC-induced AR were observed am ong the treatments. However, the use of caffeine resulted in greater freque ncy of sperm with the capacitated pattern by CTC staining, compared to cont rols without caffeine. The great est frequency of capacitated sperm (53%) w as observed with 7.5 muM caffeine. Different calcium and caffeine concentra tions in swim-up resulted in no significant differences in the cleavage rat e and embryo development. In summary, micromolar concentrations of caffeine in Sperm Talp may stimulate sperm capacitation. (C) 2001 Elsevier Science B.V. All rights reserved.