ACUTE GLUCOSURIA AFTER CONTINUOUS GLUCOCORTICOID LOADING IN THE RAT IN-VIVO

We investigated the effects of the continuous infusion of various ster oids in rats on renal tubular reabsorption of glucose in vivo to eluci date the pathogenesis of steroid-induced glucosuria. Urinary glucose e xcretion increased 60 min after administration of dexamethasone (2.38 mM). By 120 min, urinary excretion of glucose was three times higher i n the dexamethasone group than in the control group (24.1 +/- 4.6 vers us 72.4 +/- 16.7 mu mol); the plasma level of glucose did not increase . Dexamethasone had no effect on the resorption of 1,5-anhydro-D-gluci tol, which is a glucose-resembling polyol that is actively absorbed by the renal tubules as glucose. Neither estradiol nor progesterone incr eased urinary excretion of glucose. These findings suggest that contin uous administration of a high-dose glucocorticoid selectively influenc es the glucose reabsorption system in the kidney. (C) 1998 Elsevier Sc ience B.V.