THE INFLUENCE OF CORTISOL ON 2-DEOXYGLUCOSE PENETRATION AND PHOSPHORYLATION BY THE MOUSE EAR STRIP PREPARATION

Abstract

ABSTRACT The influence of cortisol on 2-deoxyglucose (2-DG) penetration and phosphorylation was studied using the mouse ear strip preparation. The inhibitory effect of cortisol on 2-DG metabolism was first detectable only after a 1 h pre-incubation with cortisol. Cortisol inhibition of 2-DG phosphorylation became evident within 5 min after the addition of 2-G to the incubation medium, a significant inhibition of 2-DG penetration being induced 2 h later. This latter observation is interpreted as reflecting that small differences in intracellular 2-DG between the control and the experimental flasks would be masked by the variation within larger extracellular 2-DG pools during the early time periods. In longer incubation the rate of 2-DG phosphorylation slowed or stopped after 5 h of incubation and hence the increase of intracellular 2-DG accumulation had to be considered. At later time periods, cortisol inhibition of 2-DG penetration became clearly evident. The data are considered to be most consistent with a cortisol effect resulting in a decreased penetration of this sugar through the cell membrane.