The pancreas functions as both an endocrine and exocrine gland. The endocrine component consists of the islets of Langerhans, whereas the exocrine tissue produces digestive enzymes through the ductal system. Although the majority of Type I Diabetes research has focused on the islets, the exocrine tissue is likely implicated in T1D as well. This research utilizes a novel method to investigate exocrine pancreas metabolism with a pancreas perfusion system. I hypothesized that dissolution dynamic nuclear polarization (dDNP) combined with the pancreas perfusion system would provide real-time measurements of central carbon metabolic turnover in the exocrine pancreas. DNP is a phenomenon in which a transfer of high spin polarization greatly enhances the signal in the resulting nuclear magnetic resonance (NMR) spectra. This research compares dDNP measurements in the exocrine pancreas in C57BL/6 male mice under varying glucose conditions. It also examines central carbon metabolism using this system in the T1D mouse model NOD.Rag1-/-.AI4α/β and the NOD.Rag1-/- control. After cannulation of the common bile duct, the exocrine pancreas was perfused for 30 minutes with perfusate containing either 3mM or 16.7mM glucose. Tissue viability was confirmed throughout the perfusion with oxygen consumption measurements. dDNP was performed using the trityl radical and 4mM [1-13C]pyruvate. NMR spectra were collected on a 600MHz instrument with a 10mm [13C]-optimized cryoprobe and analyzed with Bruker TopSpin. Several metabolites were identified and quantified in all measured spectra, demonstrating the detection of real-time metabolic turnover. Ultimately, this work demonstrates that dissolution dynamic nuclear polarization can be used to evaluate metabolic flux in the pancreas in multiple mouse models. Future will investigate the real-time metabolic response of the exocrine pancreas to insulin concentrations in the T1D disease model.
A.Rushin: None. M.Mcleod: None. M.Ragavan: None. M.Merritt: None.
National Institutes of Health (T32 DK10876) National Science Foundation (DMR-1644779)