title: Imaging the pancreatic vasculature in diabetes models.
abstract: BACKGROUND
  Vascular parameters, such as vascular volume, flow, and permeability, are important disease biomarkers for both type 1 and type 2 diabetes. Therefore, it is essential to develop approaches to monitor the changes in pancreatic microvasculature non-invasively.
  
  
  METHODS
  Here, we describe the application of the long-circulating, paramagnetic T1 contrast agent, protected Graft Copolymer bearing covalently linked gadolinium diethylenetriaminepentaacetic acid residues and labelled with fluorescein (PGC-GdDTPA-F) for the non-invasive semi-quantitative evaluation of vascular changes in diabetic models using magnetic resonance imaging.
  
  
  RESULTS
  We observed a significantly higher accumulation of protected graft copolymer bearing covalently linked gadolinium diethylenetriaminepentaacetic acid residues and labelled with fluorescein in the pancreata of BBDR rats induced to develop diabetes, as compared to non-diabetic controls at 1 h post-injection. No differences were seen in the blood pool, kidney, or muscle, indicating that the effect is specific to the diabetic pancreas. Fluorescence microscopy revealed a marked increase in contrast agent availability in the pancreas with the development of the pathology. Similar changes were noted in the homozygous Leprdb mouse model of type 2 diabetes. This effect appeared to result both from the increase of vascular volume and permeability.
  
  
  CONCLUSIONS
  High-molecular weight paramagnetic blood volume contrast agents are valuable for the in vivo definition of pancreatic microvasculature dynamics by magnetic resonance imaging. The increase in vascular volume and permeability, associated with diabetic inflammation, can be monitored non-invasively and semi-quantitatively by magnetic resonance imaging in diabetic BBDR rats. This imaging strategy represents a valuable research tool for better understanding of the pathologic process.
authors: Molecular Imaging Laboratory, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Boston, MA, USA.
authors: Zdravka
authors: Z
authors: Medarova
authors: Dale L
authors: DL
authors: Greiner
authors: Marytheresa
authors: M
authors: Ifediba
authors: Guangping
authors: G
authors: Dai
authors: Elijah
authors: E
authors: Bolotin
authors: Gerardo
authors: G
authors: Castillo
authors: Alexei
authors: A
authors: Bogdanov
authors: Mohanraja
authors: M
authors: Kumar
authors: Anna
authors: A
authors: Moore
mesh_terms: D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000473:pathology*; D016650:Fluorescein-5-isothiocyanate; D019786:Gadolinium DTPA; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D010179:Pancreas / Q000098:blood supply*; D051381:Rats
chemical_list: D016650:Fluorescein-5-isothiocyanate; D019786:Gadolinium DTPA