Correlation between angiogenesis and islet graft function in diabetic mice: magnetic resonance imaging assessment

Abstract

Background/purpose: Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was used to evaluate neovascularization after intravenous injection of gadolinium, where contrast leaks out of new vessels and remains within the tissues. We examined the relationship between DCE-MRI and metabolic parameters such as blood glucose, serum insulin and glucose tolerance test (GTT) after intraportal islet transplantation.

Methods: Streptozotocin-induced diabetic BALB/c mice (n = 15) received syngeneic intraportal islet transplantation (500 islet equivalent). Blood glucose, serum insulin and GTT were evaluated till postoperative day (POD) 14. Liver DCE-MRI was performed at POD 3, 7 and 14. Correlations between DCE-MRI and metabolic parameters were examined using regression analysis.

Results: Eight mice achieved normoglycemia after intraportal transplantation. At POD 3 a significant but moderate correlation between DCE-MRI and blood glucose was found. No DCE-MRI or metabolic parameters correlated at POD 7. However, at POD 14 strong or moderate correlations between DCE-MRIs were found: negative correlations with blood glucose (R (2) = 0.86) and GTT (R (2) = 0.48) but a positive correlation with serum insulin (R (2) = 0.32).

Conclusion: We report that DCE-MRI can reflect the metabolic and functional condition of the transplanted islets.