Compartmentalization of glucose utilization after intravenous vs intratracheal challenge with LPS

The rate of glucose utilization (R(g)) of various tissues including lung and bronchoalveolar lavage (BAL) fluid 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 lipopolysaccarrhide (LPS). After intravenous LPS, R(g) increased in whole lung and nonrespiratory tissues, but was unaltered in BAL cells. After intratracheal LPS, the R(g) of nonrespiratory tissues was unchanged, but the R(g) of BAL cells increased from 3.7 +/- 0.3 to 71.5 +/- 16.0 nmol/min. This increase in the R(g) of BAL cells was explained by a doubling of the macrophage specific R(g), by a 100-fold increase in polymorphonuclear leukocytes (PMN) number, and by a higher R(g) 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.