Figure 5.

Percentage of PD that either degenerated or cleaved after 2.5 days in culture following incubation with or without spermatozoa in CM, CM + 2.5 mM procaine, CM—NaCl, CM—Na⁺, CM + 25 mM NH₄Cl, and CM at pH 7.9. CM at pH 7.9 had a severe degenerative effect on oocytes. In the presence of 2.5 mM procaine and 25 mM NH₄Cl, oocytes cleaved up to the 8-cell stage. Data represent mean (±SD) percentages of oocytes after incubation in CM (black bars), CM + 2.5 mM procaine (dark grey bars), CM—NaCl (light grey bars), CM—Na⁺ (white bars), CM + 25 mM NH₄Cl (hatched bars), and CM pH 7.9 (dotted bars); n = 20 oocytes in each group, three replicates. Values that differ significantly (P < 0.05) are indicated by different small letters for degenerated oocytes or capitals for cleavage.