Fig. 2. Relative abundance of glucokinase (GK) mRNA expression in liver (A), hypothalamus (B), hindbrain (C) and Brockmann bodies (D) of rainbow trout sampled 6 h after intracerebroventricular injection 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%). Relative abundance of RT–PCR products is presented in arbitrary units as mean ± s.e.m. (N=4) between GK and 18s expression. Different letters indicate significant differences among treated groups within each treatment (one-way ANOVA, P<0.05).