Fig. 3.

Rates of endogenous glucose production in 3 protocols conducted in catheterized dogs. Glucagon and insulin were clamped in all protocols using somatostatin to suppress the endogenous release of these hormones. Glucagon and insulin were replaced at basal rates in the hepatic portal vein during rest. Glucagon and insulin responses to exercise were simulated (green), glucagon response to exercise was simulated and insulin was kept at basal (red), or glucagon and insulin concentrations were both maintained at basal (blue) during exercise. Data are means ± SE. Data are from Wasserman et al. (14, 99).