MEMRI of Glucose Activated Human Pancreatic Islets
Leoni L, Haque M, Serai S, Roman B, Oberholzer J, Magin R
University of Chicago
The validity of MEMRI in assessing human pancreatic islet function was investigated. Glucose stimulated influx of calcium into -cells is necessary for insulin release. When present during glucose stimulation, extracellular Mn can enter -cells through voltage-gated calcium channels and its accumulation alters T1 and T2 relaxation times resulting in increased MR image contrast. High-resolution MR micro imaging of glucose activated isolated human islets showed a significant increase in MR contrast at 50 M Mn and higher. Although concerns may exist about Mn toxicity, the doses employed did not exhibit any acute negative effects as glucose stimulation indices were normal.