Dexmedetomidine reduces isoflurane-induced neuroapoptosis through regulating BDNF and proBDNF

Abstract Background: It is well-acknowledged that Isoflurane induces neuroapoptosis in neonatal rats. Dexmedetomidine, as an α2-adrenergic agonist, was previously demonstrated to provide neuroprotection when administered during isoflurane anesthesia. Our study aims to investigate the mechanisms concerning the neuroprotective effect of dexmedetomidine from the alterations of BDNF,ERK, and JNK signals in the hippocampal region. Methods: Neonatal Sprague-Dawley rats at postnatal day 7 were assigned into Control group, Isoflurane group, Dexmedetomidine group and Inhibitor group. After exposed to 2% isoflurane in 40% of oxygen mixed with nitrogen for 4h, the hippocampus tissues were separated and critical signal pathway proteins of BDNF, proBDNF, JNK, ERK, and caspase 3 were detected. Results: Neuroapoptosis was triggered by Isoflurane with the increased expression of caspase 3 and TUNEL-positive cells. This effect was reversed by dexmedetomidine accompanying with up-regulation of BDNF and phospho-ERK and down-regulation of proBDNF and phospho-JNK. Conclusions: This study revealed that dexmedetomidine pretreatment can attenuate neurotoxicity caused by isoflurane in neonatal rats by regulating BDNF, proBDcNF, ERK, and JNK, which would provide a new target for neuroprotection.