Fig. 2 . Twitch force and resting tension for ventricular preparations from yellowtail flounder subjected to anoxia and reoxygenation and treated with agents to affect K_ATP-channel activity. Arrows indicate times at which anoxia was induced (20 min) and when preparations were reoxygenated (55 min). (A) DMSO treated (diamonds) (N=13). (B) Glibenclamide-treated (squares) (N=8). Inset graph shows change in twitch force associated with glibenclamide treatment against time (% force from glibenclamide-treated preparations — % force from DMSO-treated preparations). (C) Diazoxide treated (hexagons) (N=5). Inset graph shows alterations in twitch force associated with diazoxide treatment against time (% force from diazoxide-treated preparations — % force from DMSO-treated preparations). (D) 5HD-treated (triangles) (N=6). Inset graph shows alterations in twitch force associated with 5HD treatment against time (% force from 5HD treated preparations — % force from untreated preparations). `a' indicates significant difference between pharmacological treatment and appropriate control. `b' indicates a significant change from measurements within the treatment taken 5 min beforehand.