Imaging pancreas in healthy and diabetic rodent model using [18F]fallypride positron emission tomography/computed tomography.
BACKGROUND
A noninvasive method of monitoring the loss of islet cells can provide an earlier and improved diagnosis for therapeutics development of preclinical phases of diabetes. The use of [(18)F]fallypride, a dopamine D2/D3 receptor radiotracer, has been developed as a surrogate marker to evaluate loss of pancreatic islet cells in a rodent model of type 1 diabetes.


METHODS
Healthy Sprague-Dawley rats were administered [(18)F]fallypride and imaged for 2 h in a positron emission tomography (PET)/computed tomography (CT) scan. Diabetes was then induced in the same rats by administration of streptozotocin, and a PET/CT scan was performed 4 days after establishing diabetes. Pancreata of a separate set of rats were evaluated by insulin immunostaining for loss of islet cells by streptozotocin.


RESULTS
Blood glucose levels of 125 mg/dL and 550 mg/dL were established for those rats without and with diabetes, respectively. [(18)F]Fallypride uptake in the pancreas of both groups of rats was rapid, but the rats with diabetes showed a significantly lower uptake (less than 50%). The specific binding ratio was decreased by 77% in the diabetic rats.


CONCLUSIONS
[(18)F]Fallypride can be a useful surrogate marker for monitoring changes in pancreatic islet cells, thus providing a noninvasive method to evaluate efficacy of therapeutics.
Preclinical Imaging, Department of Radiological Sciences, University of California-Irvine , Irvine, California.
Adriana
A
Garcia
Archana
A
Venugopal
Min-Liang
ML
Pan
Jogeshwar
J
Mukherjee
D000818:Animals; D001549:Benzamides; D001692:Biological Transport; D003921:Diabetes Mellitus, Experimental / Q000000981:diagnostic imaging* / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism*; D005462:Fluorine Radioisotopes; D007515:Islets of Langerhans / Q000000981:diagnostic imaging* / Q000378:metabolism; D008297:Male; D049268:Positron-Emission Tomography; D011759:Pyrrolidines; D051381:Rats; D017207:Rats, Sprague-Dawley; D013311:Streptozocin
D001549:Benzamides; D005462:Fluorine Radioisotopes; C094948:N-((1-allyl-2-pyrrolidinyl)methyl)-5-(3-fluoropropyl)-2,3-dimethoxybenzamide; D011759:Pyrrolidines; D013311:Streptozocin