抄録
The effect of Troglitazone (Tro) on the proliferation of Wistar rat pancreatic islet β cells was evaluated immunohistologically. The rats were divided into a standard-diet group (control group, n=9), a fructosecontaining diet group (FRU group, n=8), and a fructose-containing diet plus Troglitazone (70 mg/kg, per os) group (Tro group, n=9). In the Tro group, the pancreatic islet β cell area determined by imuunological staining using a specific antibody against rat insulin was significantly lower in comparison with the control and FRU group. To elucidate the mechanisms, Tro was added to cultured MIN6 cells. Tro (0.2, 2, and 20 μg/ml) significantly and dose-dependently reduced the BrdU-labeled MIN6 cell number without affecting cell viability. Prolactin (PRL) increased the number of BrdU-labeled cells 1.7-times as compared to the controls, which was decreased by adding 2 μg/ml of Tro, while phorbor myristate acetate (PMA) did not affect the BrdU-labeled cell number. These results suggest the possibility that Tro inhibits pancreatic islet β cell proliferation mainly through blocking the system mediated via PRL receptors (JAK-STAT system).
