Spermicidal Activity of Oxovanadium: RESULTS(7)
Changes in the plasma membrane of the cell surface also appear early in cells undergoing apoptosis. In ap-optotic cells, the membrane phospholipid phosphatidyl serine is translocated from the inner to the outer leaflet of the plasma membrane, thereby exposing phosphatidyl serine to the external cellular environment. Annexin V binds to phosphatidyl serine residues that are exposed on the surface of cells undergoing apoptosis. The apoptosis-dependent surface binding of FITC-labeled recombinant human Annexin. buy cipro
V with 10 of the 11 oxovanadium(IV) complex-treated sperm showed a dramatic increase in binding of Annexin
V to sperm membrane (Table 3). After 12 h of incubation, 26-99% (p < 0.05) of the treated sperm were apoptotic. Control sperm exhibited minimal fluorescence (Fig. 4C). By contrast, 99% of VO(Cl-phen)2-treated sperm were positive for FITC-Annexin V (Fig. 4D), indicating that surface membrane alteration occurred after prolonged exposure to oxovanadium(IV) complexes. Control sperm treated with 0.1% DMSO alone showed only 7 ± 3% Annexin V pos-itivity at 12 h. The most potent spermicidal complexes, VO(Cl-phen)2 and VO(phen)2, also induced maximum An-nexin V positivity.