Metabolic background for glucose tolerance: mechanism for epinephrine-induced impairment

Turnover rates of blood glucose in rats were calculated from the decay of [14C]glucose. A glucose load suppressed glucose appearance and this was reversed by epinephrine or glucagon. Incorporation of [14C]bicarbonate into liver glycogen and blood glucose demonstrated that these hormones did not alter gluconeogetic rate but, rather the proportion of glucose recovered in the two products. The glucose enhanced by glucagon, probably through increased insulin secretion. In contrast, epinephrine decreased peripheral glucose uptake.