title: Intermittent hypoxia maintains glycemia in streptozotocin-induced diabetic rats.
abstract: Increasing studies have shown protective effects of intermittent hypoxia on brain injury and heart ischemia. However, the effect of intermittent hypoxia on blood glucose metabolism, especially in diabetic conditions, is rarely observed. The aim of this study was to investigate whether intermittent hypoxia influences blood glucose metabolism in type 1 diabetic rats. Streptozotocin-induced diabetic adult rats and age-matched control rats were treated with intermittent hypoxia (at an altitude of 3 km, 4 h per day for 3 weeks) or normoxia as control. Fasting blood glucose, body weight, plasma fructosamine, plasma insulin, homeostasis model assessment of insulin resistance (HOMA-IR), pancreas β-cell mass, and hepatic and soleus glycogen were measured. Compared with diabetic rats before treatment, the level of fasting blood glucose in diabetic rats after normoxic treatment was increased (19.88 ± 5.69 mmol/L vs. 14.79 ± 5.84 mmol/L, p < 0.05), while it was not different in diabetic rats after hypoxic treatment (13.14 ± 5.77 mmol/L vs. 14.79 ± 5.84 mmol/L, p > 0.05). Meanwhile, fasting blood glucose in diabetic rats after hypoxic treatment was also lower than that in diabetic rats after normoxic treatment (13.14 ± 5.77 mmol/L vs. 19.88 ± 5.69 mmol/L, p<0.05). Plasma fructosamine in diabetic rats receiving intermittent hypoxia was significantly lower than that in diabetic rats receiving normoxia (1.28 ± 0.11 vs. 1.39 ± 0.11, p < 0.05), while there were no significant changes in body weight, plasma insulin and β-cell mass. HOMA-IR in diabetic rats after hypoxic treatment was also lower compared with diabetic rats after normoxic treatment (3.48 ± 0.48 vs. 3.86 ± 0.42, p < 0.05). Moreover, intermittent hypoxia showed effect on the increase of soleus glycogen but not hepatic glycogen. We conclude that intermittent hypoxia maintains glycemia in streptozotocin-induced diabetic rats and its regulation on muscular glycogenesis may play a role in the underlying mechanism.
authors.affiliation: Department of Brain Protection and Plasticity, Institute of Basic Medical Sciences, No.27 Taiping Road, Beijing, 100850, People's Republic of China.|Department of Ophthalmology, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing, 100853, People's Republic of China.
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Brain Protection and Plasticity, Institute of Basic Medical Sciences, No.27 Taiping Road, Beijing, 100850, People's Republic of China.
authors.forename: Tong
authors.initials: T
authors.lastname: Zhao
authors.affiliation: Department of Brain Protection and Plasticity, Institute of Basic Medical Sciences, No.27 Taiping Road, Beijing, 100850, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Huang
authors.affiliation: Department of Brain Protection and Plasticity, Institute of Basic Medical Sciences, No.27 Taiping Road, Beijing, 100850, People's Republic of China.
authors.forename: Liying
authors.initials: L
authors.lastname: Wu
authors.affiliation: Department of Brain Protection and Plasticity, Institute of Basic Medical Sciences, No.27 Taiping Road, Beijing, 100850, People's Republic of China.
authors.forename: Kuiwu
authors.initials: K
authors.lastname: Wu
authors.affiliation: Department of Brain Protection and Plasticity, Institute of Basic Medical Sciences, No.27 Taiping Road, Beijing, 100850, People's Republic of China. fanmingchina@126.com.
authors.forename: Ming
authors.initials: M
authors.lastname: Fan
authors.affiliation: Department of Brain Protection and Plasticity, Institute of Basic Medical Sciences, No.27 Taiping Road, Beijing, 100850, People's Republic of China. linglingzhuamms@126.com.
authors.forename: Lingling
authors.initials: L
authors.lastname: Zhu
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000503:physiopathology*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000503:physiopathology*; D019270:Fructosamine / Q000097:blood; D006003:Glycogen / Q000378:metabolism; D006801:Humans; D000860:Hypoxia; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D050417:Insulin-Secreting Cells; D008099:Liver / Q000378:metabolism; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism; D051381:Rats
chemical_list: D001786:Blood Glucose; D007328:Insulin; D019270:Fructosamine; D006003:Glycogen
keywords: Blood glucose metabolism; Glycogen; Intermittent hypoxia; Type 1 diabetes