[Serum citrulline: a potential marker for intestinal epithelial mass and absorption capacity in short bowel syndrome patients].

OBJECTIVE: To investigate the potential role of serum citrulline level in evaluating the intestinal absorptive area and capacity in patients with short bowel syndrome (SBS). METHODS: Serum citrulline concentration was determined using high performance liquid chromatography (HPLC) in SBS patients (n=22) and healthy controls (n=33). In SBS patients, the remnant small bowel lengths and diameters were measured by radiography, and their 5- hour urine D- xylose excretion and intestinal protein absorption were also determined. The correlationship of serum citrulline level with remnant small bowel length, surface area, protein and D- xylose absorption was analyzed. The 6 patients receiving intestinal rehabilitative therapy, serum citrulline level, protein and D- xylose absorption after therapy were also measured. RESULTS: Serum citrulline level of SBS patients was significantly lower than that of healthy controls [(5.94+/- 2.65) vs [(16.87 +/- 5.97) micromol/L, P < 0.01]. In SBS patients, serum citrulline was positively correlated with remnant small bowel length and surface area (r=0.82 and r=0.86 respectively). There was also a significant correlationship of serum citrulline level with 5- hour D- xylose excretion (r=0.56) and intestinal protein absorption (r=0.48). Serum citrulline, 5- hour D- xylose excretion and intestinal protein absorption were all significantly raised in patients after rehabilitative therapy, although no correlation of increasing percentage was found among above three parameters. CONCLUSIONS: Serum citrulline concentration is positively correlated with intestinal absorptive area and capacity in SBS patients. It is a potential marker for evaluating the severity of intestinal failure and the efficacy of rehabilitative therapy in short bowel patients.

Intestinal barrier damage caused by trauma and lipopolysaccharide.

AIM: To investigate the intestinal barrier function damage induced by trauma and infection in rats. METHODS: Experimental models of surgical trauma and infection were established in rats. Adult Sprague-Dawley rats were divided into 4 groups: control group (n = 8), EN group (n = 10), PN group (n = 9) and Sep group (n = 8). The rats in PN and Sep groups were made into PN models that received isonitrogenous, isocaloric and isovolumic TPN solution during the 7-d period. Rats in EN and Sep groups received laparotomy and cervical catheterization on day 1 and received lipopolysaccharide injection intraperitoneally on d 7. On the 7(th) day all the animals were gavaged with lactulose and mannitol to test the intestinal permeability. Twenty-four hours later samples were collected and examined. RESULTS: The inflammatory responses became gradually aggravated from EN group to Sep group. The mucosal structure of small intestine was markedly impaired in PN and Sep groups. There was a low response in IgA level in Sep group when compared with that of EN group. Lipopolysaccharide injection also increased the nitric oxide levels in the plasma of the rats. The intestinal permeability and bacterial translocation increased significantly in Sep group compared with that of control group. CONCLUSION: One wk of parenteral nutrition causes an atrophy of the intestinal mucosa and results in a moderate inflammatory reaction in the rats. Endotoxemia aggravates the inflammatory responses that caused by laparotomy plus TPN, increases the production of nitric oxide in the body, and damages the intestinal barrier function.

Functional hepatic flow in patients with liver cirrhosis.

AIM: To evaluate hepatic reserve function by investigating the change of functional hepatic flow and total hepatic flow in cirrhotic patients with portal hypertension. METHODS: HPLC method was employed for the determination of concentration of D-sorbitol in human plasma and urine. The functional hepatic flow (FHF) and total hepatic flow (THF) were determined by means of modified hepatic clearance of D-sorbitol combined with duplex doppler color sonography in 20 patients with cirrhosis and 10 healthy volunteers. RESULTS: FHF, evaluated by means of the D-sorbitol clearance, was significantly reduced in patients with cirrhosis in comparison to controls (764.74+/-167.91 vs 1195.04+/-242.97 mL/min, P<0.01). While THF was significantly increased in patients with cirrhosis in comparison to controls (1605.23+/-279.99 vs 1256.12+/-198.34 mL/min, P<0.01). Portal blood flow and hepatic artery flow all were increased in cirrhosis compared to controls (P<0.05 and P<0.01). D-sorbitol total clearance was significantly reduced in cirrhosis compared to control (P<0.01), while D-sorbitol renal clearance was significantly increased in cirrhosis (P<0.05). In controls FHF was similar to THF (1195.05+/-242.97 vs 1256.12+/-198.34 mL/min, P=0.636), while FHF was significantly reduced compared with THF in cirrhosis (764.74+/-167.91 vs 1605.23+/-279.99 mL/min, P<0.01). CONCLUSION: Our method that combined modified hepatic clearance of D-sorbitol with duplex doppler color sonography is effective in the measurement of FHF and THF. FHF can be used to estimate hepatic reserve function.

Prophylactic treatment with growth hormone improves intestinal barrier function and alleviates bacterial translocation in stressed rats.

BACKGROUND: Damage to the gut barrier often occurs during critical illnesses. In such cases, it is very important to alleviate impairment of the intestinal barrier and protect intestinal barrier function. This study investigated the protective effect of growth hormone on intestinal barrier function in rats under stress. METHODS: This study consisted of prospective, randomized, and controlled animal experiments. Twenty-five Sprague-Dawley rats served as total parenteral nutrition (TPN) models and were divided into three groups: TPN group, sepsis (Sep) group, and growth hormone (GH) group. Another 8 rats served as normal controls. Each group received different stress stimuli. Rats were fed for 7 days, and samples were taken for examination 24 hours after gavaging with dual saccharides. RESULTS: The architecture of the small intestinal mucosa in the Sep group showed the most severe damage among all groups. Nitric oxide levels in blood plasma and immunoglobulin A levels in the intestinal mucosa of the GH group were significantly lower than in the Sep group (P < 0.02). There were no significant changes in CD3 counts and in the CD4/CD8 ratio between the four groups. Dual sugar tests and bacteriological examinations revealed that intestinal permeability and rate of bacterial translocation in the GH group were lower than in the Sep group (P < 0.01, respectively). CONCLUSION: Prophylactic treatment with growth hormone can alleviate damage to intestinal barrier function caused by trauma and endotoxemia in rats under stress.

Evaluation of various solutions for small bowel graft preservation.

AIM:To elucidate the effect of various solutions for small bowel graft preservation in pigs under hypothermic storage.METHODS:The swine segmental small bowel graft was autotransplanted after it was preserved with lactated Ringer's (LR), Euro-Collins (EC), hyperosmolarity citrate adenine (HC-A) and WMO-1 solutions for 10,18 and 24 hours,respectively.The recipient survival rate, morphological structure, graft mucosal energy substances and Na( +) -K(+) ATPase activity were studied,and graft absorption was estimated with D-xylose absorption test.RESULTS:The morphological study of the grafts preserved with LR or HC-A solution for 10 hours or with EC and WMO-1 solution for 18 hours was normal 6days after operation. Mucosal ATP,total adenine nucleotides (TAN) contents and Na( +) -K(+)ATPase activity of the graft preserved with EC or WMO solution were higher than that of the graft preserved with LR or HC-A solution.Serum level of D-xylose was higher in EC and WMO-1 groups than in LR and HC-A groups when the graft was preserved for 24 hours.CONCLUSION:EC and WMO-1 solutions can preserve the swine small bowel up to 18 hours, which are superior to LR and HC-A solutions.