Expression of carbonic anhydrase II in human testes and spermatozoa and its clinical significance / 中华男科学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the expression of carbonic anhydrase II (CA2) in human testes and spermatozoa, and to compare the expressions of CA2 in ejaculated spermatozoa between normozoospermic and asthenozoospermic men.</p><p><b>METHODS</b>The localization of CA2 in human testes was observed by immunohistochemistry, and that in human sperm by immunofluorescence. Western blot was used to detect the expression of CA2 in the semen samples obtained from 16 normozoospermic and 16 asthenozoospermic volunteers.</p><p><b>RESULTS</b>The CA2 protein was shown to be localized in the tail of elongating spermatids by immunohistochemistry and in the flagellum of human sperm by immunofluorescence. Western blot revealed an obviously increased expression of CA2 in the spermatozoa of asthenozoospermic patients, with statistically significant difference from the normozoospermic group (1.84 +/- 0.32 vs 1.41 +/- 0.26, P < 0.05).</p><p><b>CONCLUSION</b>The CA2 protein is expressed in the spermatogenic stage of elongating spermatids in human testes and localized in the sperm tail. The expression of CA2 is significantly increased in the spermatozoa of asthenozoospermic men, which might be responsible for low sperm motility.</p>