Online LC-MS/MS Analysis for Profiling Peptide Hormone Secretion Dynamics from Islets of Langerhans

Area of Science:

• Endocrinology and Metabolism
• Analytical Chemistry
• Biomedical Engineering

Background:

• Islets of Langerhans secrete peptide hormones essential for blood glucose homeostasis.
• Disruptions in hormone secretion patterns are linked to metabolic disorders like diabetes.
• Quantifying multiple hormones simultaneously at rapid intervals is necessary to study these dynamics.

Purpose of the Study:

• To develop an automated, online analytical system for real-time quantification of multiple peptide hormones from human islets.
• To resolve the dynamic secretion patterns of key hormones involved in glucose regulation.

Main Methods:

• An automated microfluidic system sampled perfusate from human islets.
• Sequential liquid chromatography-tandem mass spectrometry (LC-MS/MS) was performed every 2 minutes.
• A C18 column and triple quadrupole mass spectrometer enabled rapid online detection of insulin, C-peptide, glucagon, and somatostatin.

Main Results:

• The system achieved rapid separation and quantification of four key islet hormones.
• Linear calibration curves were obtained from 0.5 to 50 nM with good reproducibility (3-15% RSD).
• Observed secretion dynamics included first-phase insulin release and inverse glucagon-insulin correlation.

Conclusions:

• The developed automated LC-MS/MS method provides a valuable tool for studying islet hormone secretion dynamics.
• This approach can be applied to investigate cellular communication and secretion of other biologically relevant molecules.
• The system offers a simple yet effective platform for real-time analysis in biological systems.