Indices of glucose utilization rates (R g′) in individual tissues are summarized in Table 4. In the basal state, R g′ of the red hindlimb muscle of the Tesaglitazar group was lower than in the Obese group, representing a normalization towards the values in the Lean group. White adipose tissue R g′, elevated in Obese versus Lean, was further elevated by tesaglitazar. In all insulin responsive tissues examined (i.e., not cerebellum) tesaglitazar markedly improved the ability of insulin to concentration dependently stimulate R g′ in the obese Zucker rat. An example showing the dependence of R g′ on plasma insulin is illustrated in Figure 3 for the RQ muscle. This treatment effect was so profound that it enabled quantitative estimation of insulin sensitivity (EC50 value for R g′ as defined in Section 2) in a number of tissues of the obese rat which was generally not possible in untreated animals due to a virtual absence of insulin effect. For the Tesaglitazar treated group the EC50 for white fat, diaphragm and RG were 0.7 nM (95% CI 0.4–1.0), 1.7 nM (1.1–2.7),
