Figure 8.

(A) Intracellular pH was assessed at 0, 10, 30, and 60 min in stallion sperm suspensions (30 × 10⁶ sp/ml) exposed to NCM, CM, CM—NaCl, CM—Na⁺, CM + 25 mM NH₄Cl, and CM pH 7.9, CM + 2.5–5–10-25-50 mM procaine using the ratiometric dye BCECF-AM. Increasing procaine concentration was associated with an increase in intracellular pH. Values are mean (±SD) BCECF-AM ratios of sperm in suspensions exposed to different capacitating conditions (three replicates using three different stallions). Within each time point, values that differ significantly (P < 0.05) are indicated by different small letters. (B) Acidic sperm cell organelle pH was assessed at 0, 10, 30, and 60 min in stallion sperm suspensions (30 × 10⁶ sp/ml) exposed to NCM, CM, CM + 25 mM NH₄Cl, CM pH 7.9; and CM + 2.5 and 10 mM procaine using Lysosensor Green DND-189 dye. Increasing procaine concentration was associated with a decrease in pH of acidic sperm cell organelles. Values are mean (±SD) relative fluorescence of Lysosensor Green DND-189 of sperm in suspensions exposed to different capacitating conditions (three replicates using three different stallions). Within each time point, values that differ significantly (P < 0.05) are indicated by different small letters.