Figure 1. Hindlimb perfusion: contractile responses to electrical field stimulation (EFS) at 34 °C.

A-C, representative traces showing vasoconstrictor responses (expressed as increase in perfusion pressure, mmHg) to EFS (arrow: supramaximal voltage, 0.5 ms; 5 or 20 Hz for 10 s) from a control animal (A), a cold control animal (B) and a hibernated animal (C). The fluctuations in perfusion pressure were due to the pulsatile movements of the pump. Responses in all preparations at 20 Hz are biphasic, being twitch-like components and sustained components. D, summary of the different components elicited by the nerve stimulation: the twitch-like component from controls (○), cold controls (□) and hibernated animals (▵), and the sustained one from controls (•), cold controls (▪) and hibernated animals (▴). All results are expressed as means ±s.e.m.; n = 5-7. *P < 0.05vs. control; †P < 0.05vs. cold control.