LOCALIZATION OF CARBONIC-ANHYDRASE IN THE SPERM-STORING REGIONS OF THE TURKEY AND QUAIL OVIDUCT

The localization of carbonic anhydrase in the sperm storage regions of turkey and quail was investigated using a histochemical method showin g the activity of all the isozymes present. Intense carbonic anhydrase activity was found in the turkey sperm storage tubules and infundibul ar storage glands, whereas no activity could be detected in the quail at these sites. Both species did, however, show strong membrane-bound and cytoplasmic activity in the non-ciliated cells of the utero-vagina l surface epithelium and scattered cells of the vaginal epithelium. Th e enzyme catalyses the reaction CO2 + H2O <-> H+ + HCO3-, and the pres ence of carbonic anhydrase in these regions makes rapid changes in pH possible. It is suggested that increasing pH and/or the addition of bi carbonate stimulates sperm motility needed during transfer of the ovid ucal lumen. A lowering of the pH would keep the sperm quiescent during storage. The duration of sperm storage is considerably longer in the turkey than in the quail. The high quantity of carbonic anhydrase in t he turkey sperm storage tubules may, thus, play a role in the duration of sperm storage. (C) 1998 Chapman & Hall.