Fig. 3. Effects of insulin treatment (24 h) on the btGLUT4 protein content of red muscle and white muscle from brown trout. (A) Immunodetection of btGLUT4 and actin protein in total membrane preparations from red and white muscle. 25 µg of protein was loaded in each lane, subjected to SDS-PAGE and immunoblotted using antibodies against okGLUT4 and chicken actin. (B) Densitometric analysis of the btGLUT4/actin ratios from red muscle and white muscle. Values are means ± s.e.m. and are referred to the saline-injected group, which was set to 1 (N=5-6). ^*Significant differences compared with the saline-injected group for each type of muscle (P<0.05).