Application of a novel rectal cooling device in hypothermia therapy after cerebral hypoxia-ischemia in rats.
A new rectal cooling device for therapeutic hypothermia (TH) therapy is designed and is applied in TH treatment of SD rats with ischemic-hypoxic brain damage.



Healthy adult SD rats (n = 45) were randomly assigned into four groups: the healthy control group (n = 5), the ischemia and hypoxia group (n = 10), the rectal TH cooling group (n = 18), and the ice blanket TH cooling group (n = 11). The rats in the rectal cooling and ice blanket TH groups received 12 h treatment after hypoxic-ischemic brain damage had been established, while those in the ischemia and hypoxia group did not. Taking the start of TH as the zero point, rats were sacrificed after 24 h and the brain and rectum tissues were sampled for histological analysis.



The TH induction time (37.3 ± 14.7 min) in the rectal cooling group was significantly shorter (F = 4.937, P < 0.05) than that in the ice blanket cooling group (75.6 ± 27.2 min). The HE and NISSL staining results showed that rats in the rectal TH cooling group had significantly decreased (P < 0.01) positive neurons cell count compared to those in ischemia and hypoxia group. In addition, TUNEL staining indicated that the number of apoptotic cells (3.9 ± 1.8 cells / × 400 field) and the apoptosis index (4.4 % ± 1.5) were significantly lower in rectal TH cooling group (P < 0.05) than in ischemia and hypoxia group (23.2 ± 12.1 cells / × 400 field, 26.6 % ± 12.1). Also, no rectal frostbite or inflammatory infiltration was observed in rats in the rectal TH treatment groups.



Our new cooling device realized rapid TH induction in SD rats with ischemic-hypoxic brain damage, inhibited the apoptosis of cells in the hippocampal CAl region, and did not cause histological damage to the rectal tissues.
Department of PICU, Children's Hospital of Chongqing Medical University, Chongqing, 400014, China.|Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Chongqing, 400014, China.
Peng
P
Liu
Department of PICU, Children's Hospital of Chongqing Medical University, Chongqing, 400014, China.
Rui
R
Yang
Department of PICU, Children's Hospital of Chongqing Medical University, Chongqing, 400014, China. zuozelan@126.com.
Zelan
Z
Zuo
D000818:Animals; D017209:Apoptosis; D001831:Body Temperature; D056547:CA1 Region, Hippocampal / Q000473:pathology; D002452:Cell Count; D005260:Female; D005627:Frostbite / Q000150:complications / Q000473:pathology; D007036:Hypothermia, Induced / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods*; D020925:Hypoxia-Ischemia, Brain / Q000473:pathology / Q000628:therapy*; D007053:Ice; D007249:Inflammation / Q000150:complications / Q000473:pathology; D008297:Male; D009474:Neurons / Q000473:pathology; D051381:Rats; D012007:Rectum
D007053:Ice
Cell apoptosis; Rectal cooling device; Therapeutic hypothermia