Role of rat large intestine in reducing diarrhea after 50% or 80% distal small bowel resection

Proper Positioning and Restraint of a Rat Hind Limb for Focused High Resolution Imaging of Bone Micro-architecture Using In Vivo Micro-computed Tomography

The use of in vivo micro-computed tomography (µCT) is a powerful tool which involves the non-destructive imaging of internal structures at high resolutions in live animal models. This allows for repeated imaging of the same rodent over time. This feature not only reduces the total number of rodents required in an experimental design and thereby reduces the inter-subject variation that can arise, but also allows researchers to assess longitudinal or life-long responses to an intervention. To acquire high quality images that can be processed and analyzed to more accurately quantify outcomes of bone micro-architecture, users of in vivo µCT scanners must properly anesthetize the rat, and position and restrain the hind limb. To do this, it is imperative that the rat be anesthetized to a level of complete relaxation, and that pedal reflexes are lost. These guidelines may be modified for each individual rat, as the rate of isoflurane metabolism can vary depending on strain and body size. Proper technique for in vivo µCT image acquisition enables accurate and consistent measurement of bone micro-architecture within and across studies.

Intestinal resection and ursodeoxycholic acid: effect on hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase and acyl-CoA:cholesterol acyltransferase activities in the rat

The effect of distal small bowel resection (DSBR) and/or ursodeoxycholic-acid (UDCA) ingestion on hepatic activities of 3-hydroxy-3-methylglutaryl Coenzyme A (HMG-CoA) reductase and acyl-CoA:cholesterol acyltransferase (ACAT) was studied in rats. The total activity and the activity state of the enzyme HMG-CoA reductase were also determined. DSBR significantly increased the total activity of HMG-CoA reductase. This increase was enhanced when rats were treated with UDCA. The active form of the enzyme was increased by DSBR. However, the ingestion of UDCA did not modify these results. Therefore, the observed increase in the total activity of HMG-CoA reductase in resected-rats after the administration of UDCA was due to an increase in the inactive form of the enzyme. The activity of ACAT was decreased in resected animals. This decrease was greater after the treatment of UDCA in resected rats when compared with the corresponding group of untreated rats with UDCA. We conclude that UDCA ingestion increases the effect of intestinal resection on hepatic HMG-CoA reductase and ACAT activities.

Bacterial adaptation in patients with short bowel and colon in continuity

BACKGROUND & AIMS

Long-term carbohydrate malabsorption in patients with short bowel and colon in continuity (SBC) could result in a more efficient fermentation. The bacterial fermentation capacity in patients with SBC was assessed.

METHODS

Eleven fasting patients with SBC ingested 60 g lactulose with 10 g polyethylene glycol. Stool specimens were analyzed. Patients were compared with 8 normal subjects who ingested 60 g lactulose on two occasions, separated by 8 days during which 20 g lactulose was taken twice daily. Moreover, the daily amount of bacteria excreted in stools was measured in 6 patients with SBC and 6 normal subjects.

RESULTS

Despite fast transit time, patients fermented more lactulose and hexoses and had a higher activity of beta-galactosidase in stools than nonadapted normal subjects (P < 0.01); these parameters were roughly similar in patients and adapted normal subjects. The fecal output of short-chain fatty acids was significantly lower in patients than in nonadapted normal subjects (P < 0.03). Patients excreted a significantly greater amount of bacteria in stools than normal subjects (P < 0.05).

CONCLUSIONS

In patients with SBC, the capacity of bacterial flora to ferment lactulose and fecal bacterial mass is spontaneously increased, suggesting that hyperfermentation may affect other carbohydrates. Moreover, hyperfermentation is associated with efficient removal of extra short-chain fatty acids from fecal water.

Characterization of the lipid and fatty acid composition of rat caecal mucosa: effect of intestinal resection

The lipid composition and the fatty acid profile of the lipid fraction (phospholipid, triacylglycerol, diacylglycerol and cholesterol ester) of the caecum were studies 6 weeks after both 50% and 75% distal small bowel resection (DSBR). Triacylglycerol (TG) and cholesterol ester (CE) levels were decreased after resection but the total phospholipid (PL), free cholesterol (FC), and diacylglycerol (DG) contents were not significantly modified after the operation. Different fatty acid changes in the caecum lipid fractions were found after the surgical operation, with the greatest differences after 75% DSBR. Saturated fatty acids were increased in PL, TG and CE fractions as a consequence of DSBR. Similarly, these fractions presented the lowest amounts of n-6 and polyunsaturated fatty acids after resection. On the contrary, the levels of saturated fatty acids was decreased and both n-6 and polyunsaturated fatty acid levels increased in the DG fraction of resected animals. These results are discussed in terms of adaptation to intestinal resection.