Simultaneous Determination of Metabolites Related to Arginine Metabolism in Rat plasma by Hydrophilic Interaction Chromatography-Tandem Mass Spectrometry

Arginine and its metabolites play important roles in pain and analgesia. This study aimed to develop a comprehensive quantification method for amino acids and metabolites related to arginine metabolism in rat plasma by hydrophilic interaction chromatography-tandem mass spectrometry (HILIC-MS/MS). Rat plasma was diluted to reduce the matrix effect and deproteinized with acetonitrile. The analytes were separated on a Syncronis HILIC column with a gradient elution. MS analysis was performed in positive ion mode with an electrospray ionization source using multiple reaction monitoring technology. All calibration curves for the 10 analytes showed good linear regression (R-2 > 0.99). The limits of detection (LODs) were in the range of 0.9-13.4 mu g/L. The established method was validated for intra-day and inter-day precisions (relative standard deviation [RSDs] < 6.21%) and accuracy (average recovery ranged from 87.34% to 100.35% with the RSD values less than 11.41%). This method was successfully applied to characterize dynamic alterations in the plasma of rats with neuropathic pain and thus provide service to explore the mechanism of action between metabolite changes and clinical disease.

Automated summary

A comprehensive quantification method for amino acids and metabolites related to arginine metabolism in rat plasma was developed using hydrophilic interaction chromatography-tandem mass spectrometry (HILIC-MS/MS). The method showed good linear regression, low limits of detection, and high precision and accuracy. It was successfully applied to study dynamic alterations in the plasma of rats with neuropathic pain, providing insights into the mechanism between metabolite changes and clinical disease.