Role of hypothalamic aromatase in sevoflurane anesthesia-induced epileptic waves in neonatal rats / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the role of hypothalamic aromatase in sevoflurane anesthesia-induced epileptic waves in neonatal rats.Methods:Thirty clean-grade healthy neonatal Sprague-Dawley rats of both sexes, aged 5 days, weighing 10-15 g, were divided into 3 groups ( n=10 each) according to a random number table method: control group (group C), sevoflurane group (group S), and aromatase inhibitor formestane plus sevoflurane group (group F). The electroencephalogram (EEG) in the neonatal rat cortex was monitored, 30 min later formestane 2 mg/kg was subcutaneously injected in F group, while the equal volume of normal saline was given instead in C and S groups.At 30 min after subcutaneous administration, 6% sevoflurane was inhaled to induce anesthesia for 3 min, and then the concentration was adjusted to 2.1% to maintain anesthesia for 57 min in S and F groups.The total duration and single duration of epileptic waves and the number of seizure during sevoflurane anesthesia were recorded.After the end of EEG recording, the laparotomy was performed, the left ventricular puncture was performed, and blood samples were collected for blood gas analysis and for determination of corticosterone levels (by enzyme-linked immunosorbent assay). Brain tissues were obtained, and then the hypothalamus was rapidly isolated for determination of the expression of aromatase mRNA, Na + -K + -2Cl - cotransporter-1 (NKCC1) mRNA and K + -Cl - cotransporter-2 (KCC2) mRNA (by polymerase chain reaction). Results:No epileptic waves were found in group C. Compared with group C, the total duration and single duration of cortical epileptic waves were significantly prolonged, and the number of seizures was increased, the serum corticosterone concentration was increased, the expression of aromatase mRNA was up-regulated, and NKCC1/KCC2 mRNA ratios were increased in S and F groups ( P<0.05). Compared with group S, the total duration and single duration of cortical epileptic waves were significantly shortened, and the number of seizures was decreased, the serum corticosterone concentration was decreased, the expression of aromatase mRNA was down-regulated, and NKCC1/KCC2 mRNA ratios were decreased in group F ( P<0.05). Conclusion:Up-regulation of hypothalamic aromatase expression is involved in the development of sevoflurane anesthesia-induced epileptic waves in newborn rats.