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

Abstract

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.

Glucose and Glutamine Gavage Increase Portal Vein Nitric Oxide Metabolite Levels via Adenosine A2b Activation

“…Glutamine is a unique amino acid in many respects: it is the most abundant free amino acid in the blood, it provides energy from muscle and adipose tissue for the gut, it allows for nontoxic, interorgan transport of ammonia [35], and it promotes gut mucosal growth and barrier function [36]. In fact, intravascular glutamine might protect against total parenteral nutrition-associated intestinal atrophy [36] and enterocolitis while improving splanchnic blood flow [37]. Additionally, glutamine might provide protection to the gastrointestinal tract in pathologic conditions such as peptic and duodenal ulcers, ileitis, and enteropathies associated with malnutrition [32 for review].…”

The role of macronutrients in gastrointestinal blood flow

“…Intestinal immaturity and poor perfusion are eminent risk factors for necrotizing enterocolitis in premature neonates. In contrast to an earlier experimental study [23], Mercier et al [24] reported no benefits of enteral glutamine on mesenteric blood flow (assessed by Doppler ultrasound) in 21 healthy premature neonates (27-35 weeks of gestational age). Another randomized trial in healthy term infants aimed at investigating the effect of the supplementation of nucleotides on postprandial mesenteric blood flow.…”

Hypertaurinemia in Bile Duct–Ligated Rats After Surgery: The Effect of Gut Endotoxin Restriction on Organ Fluxes and Oxidative Status

“…11 Immediately after the microsphere procedure, the abdomen was opened and blood samples (0.4 mL) were drawn from the left renal vein, the hepatic vein, the portal vein, and aorta as earlier described in detail. 6 F were computed according to the "reference organ" technique. 14 Portal venous flow was computed as the sum of the arterial flows through the splanchnic organs (ie, the stomach, pancreas, spleen, small intestine, and colon).…”