Mesenteric arteriovenous differences in glucose, lactate and insulin concentrations in rats and humans

The present study was aimed to investigate the mesenteric arteriovenous differences in blood glucose and lactate and plasma insulin in humans (n=8) and rats (n=10). Arterial (abdominal aorta) and mesenteric vein blood glucose and lactate (enzymatic methods) and plasma insulin concentrations (radioimmunoassay) were measured in patients during abdominal surgery and in normal rats. Blood glucose levels were significantly (p < 0.05) higher in the abdominal aorta than in the mesenteric vein in both rats (9.2+/-1.0 vs 7.5+/-0.8 mmol/l) and humans (10.4+/-2.9 vs 8.5+/-2.7 mmol/l). Blood lactate levels were higher (p < 0.05) in the mesenteric vein in both rats (3.7+/-1.3 vs 2.8+/-0.9 mmol/l) and humans (0.7+/-0.23 vs 0.1+/-0.05 mmol/l). Plasma insulin concentrations were identical in the aorta or mesenteric vein in both rats (314.4+/-162.0 vs 311.4+/-94.2 pmol/l) and humans (62.4+/-43.2 vs 61.8+/-48.0 pmol/l). In conclusion, both rat and human intestine retained a high proportion of arterially administered glucose and released lactate under the studied conditions.