Metrics details. Bile acids BAs are synthesized in the liver and can mediate homeostasis and various metabolism processes in the human body.
Their levels in the gastrointestinal tract are closely related to various gastrointestinal diseases. In particular, farnesoid X receptor activated by free BAs is associated with overexpression of histidine decarboxylase in tumorigenesis. Therefore, comprehensive profiling of histamine HIST , histidine His , and BAs in biological samples can provide insight into the pathological mechanisms of gastrointestinal diseases.
However, development of an analytical platform to profile HIST, His, and BAs in biological samples has several challenges such as highly different polarities between acidic and basic targets, low physiological concentrations of analytes, and high matrix interference of biological samples. In serial derivatization, benzoyl chloride BzCl and N,N -dimethylethylenediamine DMED were used to selectively derivatize amino and carboxyl groups of analytes, respectively.
After serial derivatization, all target derivatives were determined using a reverse-phase C18 LC column and positive multiple reaction monitoring MRM mode, with reasonable chromatographic separation and sensitive MS detection. To accurately quantify target metabolites, 7 stable isotope-labeled internal standards were used.
The developed method was validated with respect to limits of detection and quantification, linearity, precision, accuracy, stability, and matrix effect. The established method was successfully applied to human gastric fluid samples. This method provides reliable quantification of HIST, His, and BAs in human gastric fluid and will be helpful to understand pathophysiological mechanisms of gastric diseases.
