Atsushi Takatori

Effects of perinatal exposure to bisphenol A on the behavior of offspring in F344 rats

The objective of this investigation is to evaluate whether perinatal maternal exposure to bisphenol A (BPA) at 4, 40, and 400 mg/kg per day affects the behavior of offspring in F344 rats. Perinatal BPA exposure inhibited the body weight increases of male and female offspring in a dose-dependent manner, which continued after weaning. Spontaneous activity analyses revealed that BPA elongated immobile time during the dark phase in female offspring. At 4 weeks of age, male offspring exposed to BPA at 40 and 400 mg/kg per day performed avoidance responses significantly higher in the shuttlebox avoidance test. At 8 weeks of age, however, male offspring only at 4 mg/kg per day showed significantly lower responses. In the open-field behavior test at 8 weeks of age, male offspring exposed to BPA only at 4 mg/kg per day showed a higher percent of grooming than the control male offspring. In conclusion, perinatal exposure to BPA caused the behavioral alterations in the offspring.

Amelioration of the β‐cell dysfunction in diabetic APA hamsters by antioxidants and AGE inhibitor treatments

In our recent report, probucol treatment ameliorated glucose intolerance and increased the insulin‐positive area in the pancreas of streptozotocin (SZ)‐induced diabetic APA hamsters. The data suggested that the beneficial effects of probucol treatment on β‐cell function might result from its additive effect as an antioxidant. Here, we examined the antioxidant effects on the β‐cell function in SZ‐induced diabetic APA hamsters treated with three different agents, N‐acetyl‐L‐cysteine (NAC), aminoguanidine (AG) and pyridoxamine (PM).

Gene expression profiling of mouse embryonic stem cell progeny differentiated by Lumelsky's protocol.

Successful conversion of embryonic stem (ES) cells into insulin-producing cells has been reported by Lumelsky et al. (Science 2001;292:1389–1394); however, it remains controversial. In this study, we investigated the properties of ES cell progeny-induced differentiation according to Lumelsky’s protocol by immunocytochemistry, oligonucleotide microarray and real-time RT-PCR. Insulin-positive cells were observed at stages 3, 4 and 5. Microarray analysis demonstrated upregulation and appearance of some genes involved in pancreatic development but not β-cell-specific functional genes in cells at stage 5. Similarly, real-time RT-PCR revealed that expression of β-cell-specific functional genes such as islet amyloid polypeptide, insulin I and II was not increased in cells at stage 5. These results suggest that terminal differentiation of ES cell progeny toward functional pancreatic β-cell is insufficient. This study also demonstrates the usefulness of multiple time-course expression profiles for validating differentiation fates of ES cell progeny.