Fig. 4. Activities of glucokinase (A), and low K_m hexokinase (B) in hindbrain (Hb), hypothalamus (Hy) and Brockmann bodies (BB) of rainbow trout sampled 6 h after intraperitoneal injection (IP treatment) of 5 ml kg^–1 of Cortland saline alone (control, C) or saline containing L-(+)-lactate (L22.5, 22.5 mg kg^–1 or L45, 45 mg kg^–1), sodium oxamate (OXA, 22.5 mg kg^–1) or D-glucose (GLU, 500 mg kg^–1), or 6 h after intracerebroventricular injection (ICV treatment) into the third ventricle of 1 µl 100 g^–1 body mass of Cortland saline alone (control, C) or containing D-glucose (GLU, 400 µg µl^–1) or L-(+)-lactate (L400, 400 µg µl^–1). Results are shown as percentages of control values (control=100%, dotted line). Each value is the mean ± s.e.m. of N=11 (IP treatment) or N=8 (ICV treatment) fish per group. Different letters indicate significant differences among treated groups within each tissue (one-way ANOVA, P<0.05). ^*Significantly different from control (dotted line) in IP treatments (P<0.05); significantly different from control (dotted line) in ICV treatments (P<0.05).