Immunohistolocalization of carbonic anhydrase isozymes (CA-I, CA-II and CA-III) in bovine male reproductive tracts

Immunohistochemical localizations of carbonic anhydrase isozymes (CA-I, CA-II and CA-III) in bovine male reproductive tracts were studied. In bulls, no immunoreaction was seen after treatment with antibodies to CA-I, -II and CA-III in the testis. Specific staining for CA-III, however, was evident in peritubular cells in interstitial tissue of the testis, epididymis. CA-II activity could be detected in epithelium of the epididymis, ductus deferentis and ampulla ductus deferentis. Especially, a strong reaction for CA-II was seen in apical in epithelium of the epididymis in the initial and middle segment. CA-I activity was only founded in ductus deferentis and ampulla ductus deferentis. No or a weak reaction for CA-I, CA-II and CA-III were seen in the three accessory reproductive glands. Specific immunostaining for CA-II and CA-I could be observed in the organ, suggesting the bicarbonate in bovine semen to derive primarily from the genital tract and not accessory reproductive organs. CA-III-positive peritubular cells in interstitial tissue were also stained for alpha smooth muscle actin, and were very similar to contractile myofibroblast cells (Wrobel et al., 1979).