Measurement of Cortisol-Stimulated Gluconeogenesis in the Rat

The rate of formation of free glucose in fasted, adrenalectomized rats treated with cortisol was measured by an isotope dilution technique during the period 2–4 hr after hormone administration. No significant increase in the rate of dilution of labeled blood glucose was found in hormone-treated animals. However, the liver carbohydrate that was stored in response to cortisol was formed from newly synthesized glucoseglucose and not from blood glucose; therefore, this accumulation of carbohydrate represented gluconeogenesis. The data indicate that, over all, gluconeogenesis is about doubled at this time after cortisol administration even though the rate of formation of free glucose is not significantly increased. In these rats cortisol treatment decreased the apparent space in which glucose was distributed. (Endocrinology85: 811, 1969)