title: Hypothyroidism affects astrocyte and microglial morphology in type 2 diabetes.
abstract: In the present study, we investigated the effects of hypothyroidism on the morphology of astrocytes and microglia in the hippocampus of Zucker diabetic fatty rats and Zucker lean control rats. To induce hypothyroidism, Zucker lean control and Zucker diabetic fatty rats at 7 weeks of age orally received the vehicle or methimazole, an anti-thyroid drug, treatment for 5 weeks and were sacrificed at 12 weeks of age in all groups for blood chemistry and immunohistochemical staining. In the methimazole-treated Zucker lean control and Zucker diabetic fatty rats, the serum circulating thyronine (T3) and thyroxine (T4) levels were significantly decreased compared to levels observed in the vehicle-treated Zucker lean control or Zucker diabetic fatty rats. This reduction was more prominent in the methimazole-treated Zucker diabetic fatty group. Glial fibrillary acidic protein immunoreactive astrocytes and ionized calcium-binding adapter molecule 1 (Iba-1)-immunoreactive microglia in the Zucker lean control and Zucker diabetic fatty group were diffusely detected in the hippocampal CA1 region and dentate gyrus. There were no significant differences in the glial fibrillary acidic protein and Iba-1 immunoreactivity in the CA1 region and dentate gyrus between Zucker lean control and Zucker diabetic fatty groups. However, in the methimazole-treated Zucker lean control and Zucker diabetic fatty groups, the processes of glial fibrillary acidic protein tive astrocytes and Iba-1 immunoreactive microglia, were significantly decreased in both the CA1 region and dentate gyrus compared to that in the vehicle-treated Zucker lean control and Zucker diabetic fatty groups. These results suggest that diabetes has no effect on the morphology of astrocytes and microglia and that hypothyroidism during the onset of diabetes prominently reduces the processes of astrocytes and microglia.
authors.affiliation: Department of Anatomy and Cell Biology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul 151-742, South Korea.
authors.forename: Sung Min
authors.initials: SM
authors.lastname: Nam
authors.affiliation: Department of Anatomy and Cell Biology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul 151-742, South Korea.
authors.forename: Yo Na
authors.initials: YN
authors.lastname: Kim
authors.affiliation: Department of Anatomy and Cell Biology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul 151-742, South Korea.
authors.forename: Dae Young
authors.initials: DY
authors.lastname: Yoo
authors.affiliation: Department of Biomedical Laboratory Science, College of Biomedical Sciences, Soonchunhyang University, Asan 336-745, South Korea.
authors.forename: Sun Shin
authors.initials: SS
authors.lastname: Yi
authors.affiliation: Department of Anatomy, College of Veterinary Medicine, Kangwon National University, Chuncheon 200-701, South Korea.
authors.forename: Jung Hoon
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Department of Anatomy and Cell Biology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul 151-742, South Korea.
authors.forename: In Koo
authors.initials: IK
authors.lastname: Hwang
authors.affiliation: Department of Anatomy and Cell Biology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul 151-742, South Korea.
authors.forename: Je Kyung
authors.initials: JK
authors.lastname: Seong
authors.affiliation: Department of Anatomy and Cell Biology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul 151-742, South Korea.
authors.forename: Yeo Sung
authors.initials: YS
authors.lastname: Yoon
keywords: Zucker diabetic fatty rat; astrocytes; complications; diabetes; grants-supported paper; hypothyroidism; methimazole; microglia; neural regeneration; neuroregeneration; obesity; thyroid hormone