Citrulline Blood Levels as Indicators of Residual Intestinal Absorption in Patients with Short Bowel Syndrome

Abstract

Plasma citrulline is known to be a marker of absorptive enterocyte mass in humans. We evaluated whether citrulline and other blood amino acids are indicators of residual small intestinal length and therefore potential predictors of dependence on parenteral nutrition in the long term. We studied 25 patients with short bowel syndrome (SBS) after at least 18 months since last digestive circuit modification; 24 of them were again evaluated 1 year later. Ten patients were weaned off parenteral nutrition and 15 were dependent on parenteral nutrition. Fifty-four healthy volunteers (28 women and 26 men) served as controls. Amino acid levels were determined on serum with high-performance liquid chromatography (HPLC) as well as on blood and serum with tandem mass spectrometry analysis. Five amino acids (citrulline, leucine, isoleucine, valine and tyrosine) were significantly lower in all SBS patients than in controls, whereas glutamine, measured only by HPLC, was significantly higher. Nevertheless, only serum citrulline measured with HPLC was significantly related to small bowel length. We conclude that HPLC remains the reference methodology to evaluate blood or serum amino acid levels in adult population with SBS.

Consumption of pasteurized human lysozyme transgenic goats’ milk alters serum metabolite profile in young pigs

“…Citrulline is a marker of intestinal absorption and function, with increased levels correlating with increased absorptive function (Jianfeng et al 2005). Increased serum citrulline levels are also correlated to morphology changes and increases in absorptive surface area of the intestine (Santarpia et al 2008; Crenn et al 2008), such as seen in the hLZ-milk fed pigs (Brundige et al 2008). Thus, the increased level of citrulline observed in the serum of the hLZ-milk fed pigs is consistent with improved GI health.…”

Intestinal Adaptation Following Resection

“…111 In several studies, plasma citrulline levels were strongly correlated with remnant small bowel length. [112][113][114][115][116] In patients with SBS, a postabsorptive plasma citrulline level of <20 µmol/L (ie, half the normal level in adult controls) was significantly associated with permanent PN dependence when measured >2 years following the last abdominal surgery. 112 However, whether citrulline levels accurately reflect the functional absorptive capacity of the small intestine remains unresolved.…”

Serum citrulline as a diagnostic marker of sepsis-induced intestinal dysfunction

“…Ileal tissue (0.1 g) was used for the measurement of intestinal glutamine concentrations by an HPLC method [21]. Ileal tissue was homogenized with saline (0.5 mL) at 4 • C, and was then combined with acetonitrile (0.5 mL).…”