Extremely short small bowel induces focal tubulointerstitial fibrosis

Massive bowel resection upregulates the intestinal mRNA expression levels of cellular retinol-binding protein II and apolipoprotein A-IV and alters the intestinal vitamin A status in rats

Short bowel (SB) syndrome causes the malabsorption of various nutrients. Among these, vitamin A is important for a number of physiological activities. Vitamin A is absorbed by epithelial cells of the small intestine and is discharged into the lymphatic vessels as a component of chylomicrons and is delivered to the liver. In the present study, we used a rat model of SB syndrome in order to assess its effects on the expression of genes associated with the absorption, transport and metabolism of vitamin A. In the rats with SB, the intestinal mRNA expression levels of cellular retinol-binding protein II (CRBP II, gene symbol Rbp2) and apolipoprotein A-IV (gene symbol Apoa4) were higher than those in the sham-operated rats, as shown by RT-qPCR. Immunohistochemical analysis revealed that absorptive epithelial cells stained positive for both CRBP II and lecithin retinol acyltransferase, which are both required for the effective esterification of vitamin A. In the rats with SB, the retinol content in the ileum and the retinyl ester content in the jejunum were lower than those in the sham-operated rats, as shown by quantitative analysis of retinol and retinyl esters by high performance liquid chromatography. These results suggest that the elevated mRNA expression levels of Rbp2 and Apoa4 in the rats with SB contribute to the effective esterification and transport of vitamin A.

Short Bowel Syndrome

This review deals with the complications and treatment of short bowel syndrome (SBS), addressing the psychosocial, medical, and surgical complications in children receiving long-term parenteral nutrition (PN) support, as well as factors that affect the intestinal adaptation process. Whenever possible, as much of the colon as possible is retained in continuity because the colon is an avid absorber of sodium. It is also important for clinicians to be aware of the important absorption mechanisms in the different regions of the bowel. For example, resection of the terminal ileum removes vitamin B12 transporters and active sodium-coupled bile salt transporters. Treatment of patients missing the terminal ileum may require monthly vitamin B12 injections and oral bile salt binders, such as cholestyramine, when the colon is present to reduce the volume of diarrhea. Patients who do not have ileocecal valves (ICVs) are prone to small bowel bacterial overgrowth that requires treatment to facilitate the intestinal adaptation process. We discuss how the PN is decreased as enteral feedings are advanced as well as clinical monitoring and routine laboratory tests. Although much has been learned over the past 20 years about PN, major questions remain, including determining the optimal form of intravenous lipid (omega-3 preparations versus omega-6 lipids versus a combination of both) to prevent liver disease.

Does L-arginine induce intestinal adaptation by epithelial growth factor?

BACKGROUND

To evaluate whether L-Arginine has an effect on endogenous epidermal growth factor secretion and intestinal adaptation in massive small bowel resection an experimental study was performed.

METHODS

Fourteen albino Wistar rats weighing 250-300 g were used for the study. After performing 50% small bowel resection and anastomosis the rats were randomly divided into two groups. The first group received 500 mg/kg/day of L-Arginine intraperitoneally for 14 days just after the surgical procedure. The control group received isotonic saline instead. Body weight measurement was preformed daily. At the end of the second postoperative week all rats underwent relaparotomy. Small bowel was resected for histopathological examination. Levels of epidermal growth factor were measured by enzyme-linked immunosorbent assay in serum, saliva, and urine at the end of second postoperative week in both groups.

RESULTS

The weight gain was higher in the L-Arginine treated group (P < 0.05). Serum, saliva and urinary epidermal growth factor levels were significantly higher at the end of the second week compared to the control group (P < 0.05). The villus height was higher on histopathological examination in L-Arginine treated group compared to the control group (P < 0.05).

CONCLUSION

L-Arginine resulted in a better intestinal adaptation after massive bowel resection. The high levels of epidermal growth factor in body fluids of L-Arginine treated rats could be the explanation for this effect.