FIGURE 4.

Overexpression of NAMPT in muscle does not protect against metabolic consequences of high fat diet. A, body weights of mice provided a standard chow diet (CD) or HFD for 24 weeks starting at 3 months of age (n = 6 mice per group). B and C, plasma non-esterified fatty acids (NEFA) and total cholesterol after 24 weeks on the indicated diets (n = 7–10 per group). D and E, glucose tolerance after 20 weeks on the indicated diets (n = 6 per group). AUC, area under the curve. F, NAD content of gastrocnemius muscles after 24 weeks on the indicated diets (n = 5–6 per group). G, oxygen consumption (VO₂) normalized to body weight after 24 weeks on the indicated diets. The time course represents the 48-h period following habituation. Shaded panels indicate periods of darkness (n = 5 per group). H, average VO₂ during light and dark periods shown in G. I, respiratory exchange ratios (RER) over the same time course shown in G. J, average respiratory exchange ratio during light and dark periods shown in I. Error bars represent S.E. *, p < 0.05; **, p < 0.01; ns, not significant by Student's t test.