Role of 5-HT 1A and 5-HT 3 receptors in sevoflurane-induced cerebral neurotoxicity in aged rats / 中华麻醉学杂志

ABSTRACT

Objective:To preliminarily investigate the relationship between the mechanism of sevoflurane-induced cerebral neurotoxicity and receptors of 5-HT 1A and 5-HT 3 in aged rats. Methods:Twenty-four clean-grade healthy male Sprague-Dawley rats, aged 18-20 months, weighing 600-750 g, were divided into 3 groups ( n=8 each) using a random number table method: group C, group LS and group HS.In group C, group LS and group HS, 50% O 2, 1.5% sevoflurane plus 50% O 2 and 3% sevoflurane plus 50% O 2 were inhaled for 2 h, respectively.Open field test was performed at 1 day before inhalation of sevoflurane and at 1 day after the end of inhalation, the time spent in the central square, the number of crossing the grid and the number of standing on the back legs were recorded.The Morris water maze test was performed at 6 days before inhalation of sevoflurane and at 1 day after the end of inhalation, the escape latency, the total swimming distance and the number of crossing the platform were recorded.Immediately after the end of behavioral testing, the hippocampal tissues were obtained for determination of 5-HT 1A and 5-HT 3 receptors mRNA expression and the number of positive cells (using real-time reverse transcription-polymerase chain reaction assay and immunohistochemical method). Results:Compared with group C, the time spent in the central square was significantly prolonged, the number of crossing the grid and the number of standing on the back legs were decreased, the escape latency was prolonged, the total swimming distance was increased, the number of crossing platform was decreased, the mRNA expression of 5-HT 1A and 5-HT 3 was down-regulated, and the number of positive cells was decreased in HS group ( P<0.05). Conclusion:The mechanism of cerebral neurotoxicity induced by sevoflurane may be related to the down-regulation of the activities of 5-HT 1A and 5-HT 3 receptors in aged rats.