Hashimoto Y, Hashimoto Y, Hirota K, Matsuki A
Department of Anesthesiology, University of Hirosaki School of Medicine, Japan.
Acta Anaesthesiol Scand. 1998 Aug;42(7):858-63. doi: 10.1111/j.1399-6576.1998.tb05334.x.
Histamine is most densely distributed in the hypothalamus and has an important effect on consciousness or wakefulness. It has been little considered whether general anesthetics could exert their effects on hypothalamic histamine metabolism. The present study was conducted to investigate the effects of isoflurane and sevoflurane anesthesia on hypothalamic histamine metabolism.
Sixty male Wistar rats were divided equally into isoflurane and sevoflurane anesthesia groups. Each group was divided into three equal sub-groups: the control, anesthesia and recovery groups. The rats of the anesthesia and recovery groups were exposed to either 2% isoflurane or 3% sevoflurane for 30 min. The recovery group was kept in air for 30 min after anesthesia. The rats were decapitated to dissect out hypothalamus which was divided into the fore and rear portion. The contents of histamine and 1-methylhistamine, which is a main histamine metabolite, were determined by high-performance liquid chromatography. The obtained data were analyzed by one-way analysis of variance followed by Bonferoni's test.
Histamine contents of the anterior and posterior hypothalamus in both isoflurane and sevoflurane groups increased significantly during the anesthesia and 1-methylhistamine contents of the anterior and posterior hypothalamus in sevoflurane group increased remarkably after anesthesia. The increases of histamine contents supposedly reflected inhibited histamine metabolism and the increases of 1-methylhistamine would be caused by acceleration of histamine degradation.
Histamine metabolism was inhibited during both isoflurane and sevoflurane anesthesia and accelerated only in the posterior hypothalamus during the emergence from these anesthetics.
组胺在下丘脑中分布最为密集，对意识或觉醒有重要影响。一般麻醉药是否会对下丘脑组胺代谢产生影响，此前很少有人考虑。本研究旨在探讨异氟烷和七氟烷麻醉对下丘脑组胺代谢的影响。
60只雄性Wistar大鼠平均分为异氟烷麻醉组和七氟烷麻醉组。每组再平均分为三个亚组：对照组、麻醉组和恢复组。麻醉组和恢复组的大鼠分别暴露于2%异氟烷或3%七氟烷中30分钟。恢复组在麻醉后置于空气中30分钟。大鼠断头后取出下丘脑，将其分为前部和后部。通过高效液相色谱法测定组胺和主要组胺代谢产物1-甲基组胺的含量。所得数据采用单因素方差分析，随后进行Bonferoni检验。
异氟烷组和七氟烷组麻醉期间下丘脑前部和后部的组胺含量均显著增加，七氟烷组麻醉后下丘脑前部和后部的1-甲基组胺含量显著增加。组胺含量的增加可能反映了组胺代谢受到抑制，而1-甲基组胺含量的增加是由组胺降解加速所致。
异氟烷和七氟烷麻醉期间组胺代谢均受到抑制，仅在从这些麻醉药苏醒过程中下丘脑后部组胺代谢加速。
