Figure 3. Effects of piridoxal phosphate-6-azophenyl-2’,4’-disulphonic acid (PPADS) and prazosin on the rapid and sustained responses evoked by electrical field stimulation (EFS) in hamster hindlimb perfusion at 34 and 10°C.

The inhibitions of control responses to EFS (arrow: supramaximal voltage, 0.5 ms; 20 Hz for 10 s) by PPADS (5 μm) and subsequently prazosin (1 μm) from a control animal and a hibernated animal at 34 and 10°C are shown. Note that at 34°C the twitch-like and sustained components of the biphasic response were almost completely abolished by PPADS and prazosin, respectively. At 10°C the monophasic response to nerve stimulation was PPADS sensitive, and the sustained component observed at 34°C, which was blocked by prazosin, was not detected.