Figure 6. TRPM8 antagonists do not inhibit the human sperm AR induced by ZP3 or progesterone (Pg).

Sperm were capacitated for ≥5 hours (see Methods) and the AR induced with 4 µM Pg (A) or recombinant human ZP3 (B) in the presence or absence of BCTC (1.6 µM) or Cz (20 µM). The ZP3 or Pg induced AR was insensitive to both inhibitors. Controls using the inhibitors alone are also shown (black bars). (C) Representative [Ca²⁺]i changes monitored after loading cells with Fluo3-AM in cell population experiments. The presence of capsazepine (black circles) did not significantly inhibit the progesterone (gray circles) induced [Ca²⁺]i increase. Scales indicate (F/F0) -1 vs time (sec). (D) Summary of the progesterone response in the absence (gray bar) or presence of 20 µM Cz or 1.6 µM BCTC (black bars), (% relative fluorescence normalized to the fluorescence obtained after the addition progesterone; n≥5).