Fig. 6. Glucose (A), glycogen (B) and lactate (C) levels, and glucokinase (D) and lactate dehydrogenase reductase (E) activities in hypothalamus of rainbow trout incubated in vitro for 1 h at 15°C in modified Hanks' medium containing 2, 4 or 8 mmol l^–1 L-(+)-lactate alone (control) or with 50 mmol l^–1 sodium oxamate, 1 mmol l^–1 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid disodium salt hydrate (DIDS), 1 mmol l^–1 sodium dichloroacetate (DCA), 10 mmol l^–1 2-deoxy-D-glucose (2-DG), 1 mmol l^–1 -cyano-4-hydroxy cinnamate (4-CIN) or 10 mmol l^–1 D-glucose. Each value is the mean ± s.e.m. of ten (control) or three (treatments) independent experiments carried out with pools of tissues from three to four different fish (21 pools per experiment: seven treatments times three glucose concentrations). Different letters indicate significant differences (P<0.05) among treatments within each lactate concentration. ^#Significantly different from groups incubated with 2 mmol l^–1 lactate within the same treatment (P<0.05); significantly different from groups incubated with 4 mmol l^–1 lactate within the same treatment (P<0.05).