Effect of progesterone on expression of brain tissue damage factors and anti damage factors in neonatal rats with hypoxic-ischemic brain damage

Objective To study the effect of progesterone on tumor necrosis factor(TNF-α), interleukin-1β(IL-1β), nerve growth factor(NGF) and brain derived neurotrophic factor(BDNF) expression in the cortex and hippocampus tissue in newborn rats with hypoxic-ischemic brain damage(HIBD), and to discuss the protective molecular mechanism of progesterone on HIBD in neonatal rats. Methods Forty-eight 7-day-old neonatal rats were randomly divided into 3 groups: sham-operated group, hypoxic-ischemic group and pretreatment group.Rats in hypoxic-ischemic group and pretreatment group were subjected to left common carotid artery ligation, then they were exposed to 80 mL/L oxygen and 920 mL/L nitrogen gas in the closed container at 37 ℃ for up to 2.5 h to establish HIBD models.Progeste-rone was injected intraperitoneally into the rats in the pretreatment group 30 min before hypoxia, and solution was injected into the first 2 groups.All the rats were killed at the 24 h after operation.The levels of TNF-α, IL-1β, NGF, BDNF were measured by enzyme linked immunosorbent assay and the expressions of TNF-α, IL-1β, NGF, BDNF mRNA were analyzed by reverse transcription-polymerase chain reaction. Results The contents of TNF-α, IL-1β, NGF, BDNF and their mRNA expressions in hypoxic-ischemic group were significantly higher than those in the sham-operated group.In pretreatment groups, the levels of TNF-α, IL-1β and their mRNA expressions were significantly lower than those in hypoxic-ischemic group.The levels of NGF, BDNF and their mRNA expressions in pretreatment group were significantly higher than those in hypoxic-ischemic group (all P<0.05). Conclusions Progesterone exerts neuroprotective effect on hypoxic-ischemic encephalopathy-induced brain damage, and the action mechanism is related to down-regulate the expression of damage factor and up-regulate the expression of anti damage factor. Key words: Progesterone; Hypoxic-ischemic brain damage; Damage factor; Anti damage factor; Neonatal rat