Compartmentalization of glucose utilization after intravenous vs. intratracheal challenge with LPS

The rate of glucose utilization (Rg) of various tissues including lung and bronchoalveolar lavage (BAL) fluids cells was measured, using the 2-deoxyglucose technique in Sprague-Dawley rats 4 h after challenge with either 1 mg/kg intravenous or 0.3 mg/kg intratracheal lipopolysaccharide (LPS). After intravenous LPS, Rg increased in whole lung and nonrespiratory tissues, but was unaltered in BAL cells. After intratracheal LPS, the Rg of nonrespiratory tissues was unchanged, but the Rg of BAL cells increased from 3.7 +/- 0.3 to 71.5 +/- 16.0 nmol/min. This increase in the Rg of BAL cells was explained by a doubling of the macrophage specific Rg, by a 100-fold increase in polymorphonuclear leukocytes (PMN) number, and by a higher Rg in PMN than in macrophages. These results demonstrate that increased glucose utilization after intratracheal LPS is confined to the respiratory system and that intra-alveolar phagocytes participate in this increase.