RESUMO
OBJECTIVE: To demonstrate the capacitance stages acquired by the spermatozoa after the in vivo contact with the endometrium and the human cervical canal. STUDY TYPE: Experimental, prospective, and longitudinal. MATERIALS AND METHODS: Spermatozoa obtained from the cervix and endometrium, plus post-capacitated semen in a 1 and 4 hours process, from couples that have proved fertility, were processed to evaluate motility, morphology, vitality and identification of morphological patterns with chlortetracycline and then inducted to acrosomal reaction with ionophore A23187. RESULTS: A safe, fast and harmless technique to obtain endometrial secretions is described. The spermatozoa capacitated in vitro and in vivo developed specific capacitance stages, applying Perry's patterns with the CTC test. Spermatozoa capacitated in vitro and then recovered in the cervix responded favorably to the induction of the acrosomal reaction with calcium ionophore A23187, differing from the obtained with endometrium wash. CONCLUSIONS: The spermatozoa recovered from the endometrium presented a more advanced capacitance stage than that obtained from the cervix, this is demonstrated with the induction of the acrosomal reaction and the CTC test. These findings suggest that endometrial and cervical tissues promote capacitance, different in each one of them and progressive in their biological route.