[Study of enteral nutrients transport in intestinal hypoperfused rat model]

To study the transport of glutamine and glucose, expression of their transporters and tissue morphology in intestinal hypoperfusion.

Sprague-Dawley rats were randomized to receive 60 min of intestinal hypoperfusion (superior mesenteric artery clamp) or serve as normoxic controls (celiotomy only). At the same time, jejunal loops were randomized to receive in situ perfusion of mannitol,glucose,or glutamine.Intestinal brush border membrane vesicles (BBMV) were prepared by calcium precipitation. Sodium-dependent uptake of glucose and glutamine into BBMV were quantitated by rapid mixing and filtration. Histologic examination and immunohistochemistry were performed by pathologists blinded to the groups.

When compared with the control group, tissue lactate concentration of the hypoperfused group increased significantly (4.9+/-0.3 vs 3.1+/-0.2), especially in the glucose perfused groups (P<0.01). Transport and transporters of glucose in brush border, but not glutamine, decreased during hypoperfusion [(76+/-10) pmol d mg(-1) d 10 s(-1) vs (290+/-13)pmol d mg(-1) d 10 s(-1)]. Tissue structural damage was most severe in glucose perfused groups during hypoperfusion.

Transport and expression of transporters of glucose and glutamine in enteral nutrition are differently regulated under conditions of trauma and stress.