Figure 5.
Dietary sulfur amino acid restriction (SAAR) alters protein synthesis and DNA synthesis in liver independent of dietary fat content. (A) Overview of the experimental groups (left) and study outline (right), designed to study the impact of dietary energy and fat content on dietary SAAR-mediated changes in liver protein synthesis and DNA synthesis. All mice were habituated to a control (Ctrl) diet for 1 wk (gray dashed line). At the start of the experimental (black solid line) period, mice were injected with deuterium oxide (D2O) intraperitoneally and then allowed free access to D2O in their drinking water. Blood and tissues were collected from 3 mice per group at each of the indicated days. (B) Protein synthesis rates (k), measured in cytosolic (left), structural/nuclear (center), and mitochondrial (right) fractions in liver. (C) DNA synthesis rates (k) in liver. n = 12–20/group. *P < 0.05 with a main effect of diet (SAAR, independent of fat content), as determined by two-factor ANOVA. Bar chart values are presented as mean ± SEM.