Patrick Antkowiak1, Moriel Vandsburger,
Frederick Epstein
1University of Virginia,
Charlottesville, VA, United States
The
kinetics and mechanism of pancreatic β cell labeling with Mn2+ were
investigated. Murine pancreatic T1 relaxation was measured in normals and
after treatment with the Ca2+ channel blocker nifedipine. Two site water
exchange analysis of pancreatic T1 relaxation provided the intracellular T1
and intracellular fraction, measures of β cell labeling. Increased
intracellular T1 and lower intracellular fraction in nifedipine-treated mice
confirmed Mn2+ enters β cells through Ca2+ channels. The timecourse of
intracellular T1 and fraction in normal mice revealed 3 phases of Mn2+
kinetics: 1) labeling β cells, 2). washout from β cells, 3).
nonspecific labeling of other cells.