Practice Test 7

During a euglycemic insulin clamp, investigators infuse insulin while maintaining plasma glucose at 5.0 mM with variable glucose infusion. They observe that hepatic glucose output decreases markedly, even though hepatocytes do not rely on GLUT4 for glucose entry. Which mechanism best explains insulin’s suppression of hepatic glucose output in this setting?

In a controlled feeding experiment, subjects consume a high-protein, low-carbohydrate meal. Plasma insulin increases modestly, and plasma glucagon increases substantially. Two hours later, plasma glucose remains stable near 4.9 mM. Which outcome is most consistent with the combined hormonal response to this meal?