Glutamine-enriched enteral diet increases splanchnic blood flow in the rat

The hemodynamic consequences of glutamine (Gln)-enriched nutrition have not been investigated. This study investigates the effects of a Gln-enriched enteral diet on organ blood flows and systemic hemodynamics. Male Fischer 344 rats (n = 24) were randomized to a group that received a 12.5% (wt/wt) Gln-enriched enteral diet or an isonitrogenous isocaloric control diet for 14 days. Blood flow measurements were performed at day 16 using 46Sc-labeled microspheres. In the Gln-enriched group, higher organ blood flows were measured in the stomach (51%), the pancreas (35%), small intestine (32%), and colon (55%), compared with controls. No differences were found in systemic hemodynamic parameters between the control and Gln-supplemented groups. A possible role for nitric oxide in this splanchnic vasodilation was investigated. Daily urinary nitrate excretion was measured during the study but showed no significant differences between the control and Gln-fed animals. No differences were found in plasma levels of the vasodilating hormone glucagon between the groups. These results show that a Gln-enriched enteral diet increased splanchnic blood flow, which was not mediated by pancreatic glucagon or increased nitric oxide production as determined by urinary nitrate excretion.