Total parenteral nutrition increases uptake of latex beads by Peyer's patches.

Background: Dysfunction of the intestinal barrier, as evidenced by increased intestinal permeability and bacterial translocation, has been reported under total parenteral nutrition (TPN). However, the role of Peyer's patches on the intestinal barrier in TPN is not well understood. We investigated whether TPN alters the uptake of microparticles by the follicle-associated epithelium of Peyer's patches. Methods: Twenty rats were divided into two groups, a control group and a TPN group. Fluorescent polystyrene latex beads, 3.2 +/- 0.2 mu m in diameter, were used as a probe for measuring the uptake by Peyer's patches. After 1 week of consuming either the control or TPN diet, rats were killed. On the day of killing, 0.1 mL, of latex beads solution was injected into 1-cm length of ileal loop, within 10 cm of the ileocecal valve. Samples were taken after 30 minutes of injection, sectioned by cryostat, and then viewed under a fluorescent microscope. Follicle-associated, epithelial length and particles were counted using a confocal laser scanning microscope. The number of particles within each compartment was standardized per unit length of epithelium of Peyer's patches. Results: Particle numbers within Peyer's patch dome of the TPN group were significantly increased compared with those of the control group (p <.01). Conclusions: These data suggest that dysfunction of the intestinal barrier in TPN might be associated with a change of uptake by Peyer's patches.