PENTOXIFYLLINE INHIBITS BASAL GLUCOSE-PRODUCTION IN HUMANS

Adenosine stimulates hepatic glucose production in vitro. To investiga te whether pentoxifylline, a xanthine derivative that blocks the adeno sine receptor, inhibits basal glucose production, we measured hepatic glucose production in eight healthy postabsorptive subjects on two occ asions: during continuous infusion of pentoxifylline and, in a control study, during saline infusion. Glucose production was measured by pri med continuous infusion of [3-H-3]glucose. Pentoxifylline infusion res ulted in an similar to 22 (volume of distribution for glucose 40 ml/kg ) to similar to 46% (volume of distribution for glucose 165 ml/kg) dec rease in basal glucose production within similar to 1 h (P < 0.05), wh ereas in the control experiment glucose production declined by only si milar to 4% in this time interval (P < 0.03 pentoxifylline vs. control ). There were no differences in concentrations of insulin, C peptide, glucagon, or catecholamines between the two experiments. Because pento xifylline inhibited glucose production in the absence of any changes i n concentrations of glucoregulatory hormones, we conclude that pentoxi fylline inhibits hepatic glucose production through other mechanisms, e.g., by blocking the adenosine receptor.