title: Differential effects of treadmill exercise on calretinin immunoreactivity in type 2 diabetic rats in early and chronic diabetic stages.
abstract: In this study, we investigated the effects of treadmill exercise on calretinin (CR), a marker of early postmitotic neurons, immunoreactivity in the dentate gyrus (DG) of Zucker diabetic fatty (ZDF) rats, before or after diabetes onset, and Zucker lean control (ZLC) rats. For this study, 6-week-old ZLC and prediabetic ZDF rats, and 22-week-old ZLC and ZDF rats were exercised on the treadmill. Sedentary ZLC and ZDF rats of the same age were used as exercise experiment controls. The exercised prediabetic ZDF rats did not show diabetes onset, while the sedentary prediabetic ZDF rats showed significantly increased blood glucose levels. The exercised diabetic ZDF rats exhibited a decrease in their blood glucose levels compared to the sedentary diabetic ZDF rats, but the levels were still above 20 mmol/l. ZLC rats of both ages were in the normoglycemic range. CR immunoreactivity was detected throughout the DG, including the subgranular zone and the polymorphic layer. Diabetic rats exhibited a significant decrease in the number of CR-immunoreactive cells and fibers in the DG. Exercise in the prediabetic ZDF rats significantly increased the number of CR-immunoreactive cells and fibers in the subgranular zone of the DG. In the ZLC and ZDF rats of chronic diabetic phase, exercise increased CR-immunoreactive neurons in the hilar region. These results suggest that diabetes significantly reduces the number of postmitotic CR-immunoreactive neurons and the intensity of immunoreactivity and that exercise increases these CR-related parameters in a diabetic stage-dependent manner.
authors.affiliation: Department of Anatomy and Cell Biology, College of Veterinary Medicine, and Research Institute for Veterinary Science, Seoul National University, Seoul, South Korea.
authors.forename: Sung Min
authors.initials: SM
authors.lastname: Nam
authors.forename: In Koo
authors.initials: IK
authors.lastname: Hwang
authors.forename: Sun Shin
authors.initials: SS
authors.lastname: Yi
authors.forename: Ki-Yeon
authors.initials: KY
authors.lastname: Yoo
authors.forename: Ok Kyu
authors.initials: OK
authors.lastname: Park
authors.forename: Bingchun
authors.initials: B
authors.lastname: Yan
authors.forename: Wook
authors.initials: W
authors.lastname: Song
authors.forename: Moo-Ho
authors.initials: MH
authors.lastname: Won
authors.forename: Yeo Sung
authors.initials: YS
authors.lastname: Yoon
authors.forename: Je Kyung
authors.initials: JK
authors.lastname: Seong
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001786:Blood Glucose / Q000378:metabolism*; D064032:Calbindin 2; D018891:Dentate Gyrus / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D004195:Disease Models, Animal; D005080:Exercise Test; D005260:Female; D007150:Immunohistochemistry; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D051381:Rats; D011924:Rats, Zucker; D064030:S100 Calcium Binding Protein G / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; C576512:Calb2 protein, rat; D064032:Calbindin 2; D064030:S100 Calcium Binding Protein G