Gut-liver interaction during accelerated gluconeogenesis

W. W. Souba and D. W. Wilmore

The effect of dexamethasone sodium phosphate on visceral organ glucose metabolism was studied in order to gain further understanding of the altered glucose dynamics that occur following catabolic states. Glucose, glutamine, and alanine exchange across the gastrointestinal (GI) tract, liver, and kidneys was determined in 25 awake dogs that were catheterized on a long-term basis during a control period and after dexamethasone sodium phosphate treatment (0.44 mg/kg/day) for two (dexamethasone 2) and nine (dexamethasone 9) days. The GI tract consumed glucose in control dogs but switched to an organ of balance or slight release with dexamethasone. Simultaneously, gut glutamine consumption increased markedly, as did intestinal alanine release. Hepatic glucose production more than doubled with dexamethasone at a time when hepatic alanine uptake was greatly increased. The kidneys demonstrated glucose balance in control animals, but released glucose with dexamethasone 9. The gut and kidneys may play an important role in the altered glucose dynamics seen in patients with sepsis and other catabolic diseases.