The goal of this proof-of-concept study is to learn if interleukin-6 changes the effect of glucagon in healthy volunteers. The main question it aims to answer is: Does IL-6 influence how effectively glucagon lowers the concentration of amino acids in blood? Researchers will compare the infusion of normal saline and a blocker of the receptor for interleukin-6 to see if blocking interluekin-6 changes how effectively glucagon lowers the concentration of amino acids in blood. Participants will be asked to * receive either an infusion of normal saline or the interleukin-6 receptor blocker * participate in a study visit three weeks later at which they will receive infusions of hormones and amino acids to mimic the concentrations of the hormones insulin and glucagon during fasting or fed conditions * labelled glucose, glycerol and amino acids will also be infused continuously to track the fate of these molecules * during the hormone infusions blood samples will be taken repeatedly