Dietary nitrogen (N) contribution to the postprandial tissue protein gain in rats 5 h after the meal. The meal was based on milk protein isolate (MPI) or rapeseed protein isolate (RPI) given for the first time (acute) or after prior 15d-adaptation to this protein source (chronic). Results are expressed as means ± SD, each bar represents 6 rats. Statistical effects are reported from an ANOVA with protein source (PS) and adaptation (A), and their interaction PS*A as factors. Bars with different letters are significantly different (P<0.05, Tukey post-hoc test).