Failure of BB FCF to affect connexin channels. Two connexins, Cx32E₁43 and Cx46, forming open “hemichannels” at regular calcium ion concentrations in oocytes expressing them, were tested. The membrane potential was clamped at −50 mV, and brief pulses to 0 mV were applied at a rate of 0.1 Hz to open the connexin channels. 100 µM BB FCF did not affect the currents carried by either connexin. The traces are representative of four trials for each connexin on different oocytes.