title: Dose response of dexmedetomidine‑induced resistance to hypoxia in mice.
abstract: Tolerance to hypoxia can be induced by reducing oxygen consumption. Dexmedetomidine (DEX) decreases locomotor activity and induces bradycardia and hypothermia in mice. The present study examined the hypothesis that DEX improves hypoxia tolerance in mice. Adult mice received an intraperitoneal injection of 1, 5, 10, 20, 40, 80, 160 or 320 µg/kg DEX, 20 mg/kg propranolol or saline. Acute hypoxic conditions were induced by placing the mice in a limited enclosed container with soda lime. Core body temperature (CBT) and heart rate (HR) were measured prior to and 30 min after drug administration. Survival time was monitored in the sealed container. Survival times (mean ± standard deviation) of mice in the saline, 1, 5, 10, 20, 40, 80, 160 and 320 µg/kg DEX, and the 20 mg/kg propranolol groups were 22.4±1.1, 23.4±1.1, 26.0±0.9, 36.9±5.2, 42.4±2.9, 43.2±2.3, 58.2±4.2, 80.5±4.0, 79.2±6.0, and 38.2±2.8 min, respectively. Pretreatment with propranolol and 10, 20, 40, 80, 160 or 320 µg/kg DEX, but not 1 or 5 µg/kg, significantly prolonged survival time compared with saline‑injected mice (P<0.05 or P<0.01). CBT and HR decreased in a similar manner. The correlation coefficients between survival time and CBT, and survival time and HR were ‑0.802 and ‑0.726, respectively. Thus, DEX dose‑dependently enhances hypoxia tolerance in mice. In conclusion, it is suggested that DEX may be used in clinical practice as a novel protective agent for organs and tissues during hypoxic injury.
authors: Department of Anesthesiology, The First Affiliated Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510080, P.R. China.
authors: Wanying
authors: W
authors: Pan
authors: Department of Anesthesiology, The First Affiliated Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510080, P.R. China.
authors: Xiaoxiao
authors: X
authors: Hua
authors: Department of Anesthesiology, The First Affiliated Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510080, P.R. China.
authors: Yueting
authors: Y
authors: Wang
authors: Department of Physiology, Zhongshan Medical College, Sun Yat‑sen University, Guangzhou, Guangdong 510080, P.R. China.
authors: Ruixian
authors: R
authors: Guo
authors: Department of Cardiovasology and Cardiac Care Unit, Huangpu Division of The First Affiliated Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510080, P.R. China.
authors: Jingfu
authors: J
authors: Chen
authors: Department of Anesthesiology, The First Affiliated Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510080, P.R. China.
authors: Liqiu
authors: L
authors: Mo
mesh_terms: D058647:Adrenergic alpha-2 Receptor Agonists / Q000008:administration & dosage / Q000627:therapeutic use*; D000818:Animals; D020927:Dexmedetomidine / Q000008:administration & dosage / Q000627:therapeutic use*; D006321:Heart / Q000187:drug effects / Q000503:physiopathology; D006339:Heart Rate / Q000187:drug effects*; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000627:therapeutic use*; D000860:Hypoxia / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D051379:Mice
chemical_list: D058647:Adrenergic alpha-2 Receptor Agonists; D006993:Hypnotics and Sedatives; D020927:Dexmedetomidine