A model of hypoxic-ischemic encephalopathy in the neonatal piglets

Abstract

Objective To duplicate a model of hypoxic-ischemic encephalopathy (HIE) in the neonatal piglets and discuss the relative issues about the model. Methods A total of 17 3-7 day healthy male piglets were randomly divided into 2 groups:sham group (n=5),and HI group (n=12). The HIE model was produced by hypoxia 40 min, room air 5 min, asphyxia 7 min and followed by reopen oxygen, CPR until ROSC. The brains were collected when the piglets were survived 4 days. Neurological deficit score (NDS) and histologic changes were studied in each group. Results There were no differences in physiologic parameters on baseline between two groups. HI group had arterial O_2 desaturation,artcrial hy-pertension,and taehycardia during the 40 min period of hypoxia and light recovery during the 5 min period of room air ventilation. During the 7 min period of asphyxia, HI groups exhibited more severe degrees of hy-poxia, severe acidosis, hypercapnia, hyperglycemia, hypotension, and bradycardia. The weight in the HI group was increased obviously slower than that in sham group (P<0.05). There were no abnormal behav-iors in sham group except day 1 showing a higher NDS due to anesthesia. The NDS was significantly in-creased in the HI group at day 1,2 and 3 after ROSC (P<0.05). Neurons were normal in sham group.The density of viable neurons in HI group was decreased to (12.6±10.1)% in pu putamen, (51.5±8.4)% in caudate and (49.1±23.4) % in sensorimotor cortex of sham group (P<0.01). Conclusion This model of HIE is successful. Systemic hypoxia followed by asphyxic cardiac arrest is well characterized physiologically and pathologically,and the pattern of brain injury closely resembles human newborn HI en-cephalopathy. Key words: Hypoxic-ischemia,Brain; Model, animal; Piglets