Quantification of the immunohistochemistry sections showed that this isoflurane anesthesia led to a 266% (P = 0.0002), 274% (P = 0.00006), and 269% (P = 0.0007) increases in TNF- immunostaining positive cells as compared to control conditions 6, 12, and 24 hours after the anesthesia, respectively (Figure 4D). microglia cells, participation of astrocytes, and involvement of neurons, has been suggested to play a role in neurodegenerative diseases, including Alzheimers disease (AD) [examined in (Akiyama et al., 2000;Cameron and Landreth, 2009;Heneka and OBanion, 2007;Sastre et al., 2006)]. Specifically, a recent Framingham study by Tan et al. (Tan et al., 2007) suggests that elevated levels of tumor necrosis factor (TNF)- and interleukin 1 (IL-1), the 4-hydroxyephedrine hydrochloride proinflammatory cytokines, in blood are associated with an increased risk of developing AD. An estimated 200 million patients worldwide undergo anesthesia and surgery each year. Several studies have shown the potential association of previous general anesthesia/surgery with the development of AD (Bohnen et al., 1994;Lee et al., 2005). However, other studies have suggested different findings (Avidan et al., 2009;Gasparini et al., 2002;Knopman et al., 2005). More population studies, especially the properly powered and multicenter human studies, are necessary to define the role of anesthesia and surgery in the development of AD (Harris and Eger, 2008). Recent studies have suggested that a transient insult, e.g., ischemia, could lead to secondary and prolonged brain injuries (van Groen et al., 2005). The inhalation anesthetics isoflurane and sevoflurane have been reported to induce such transient insults, including apoptosis, oligomerization of -amyloid protein (A), and A accumulation (Dong et al., 2009;Eckenhoff et al., 2004;Wei et al., 2008;Xie et al., 2008;Xie et al., 2006a;Xie et al., 2006b;Xie et al., 2007), which may potentially contribute to AD neuropathogenesis. However, the effects of the inhalation anesthetics on neuroinflammation have not been determined. We therefore set out to assess the effects of isoflurane, one of the most commonly used inhalation anesthetics, on the levels of proinflammatory cytokine TNF-, Interleukin-6 (IL-6) and IL-1 in main neurons and in brain tissues of both wild type and AD transgenic mice [B6.Cg-Tg(APPswe, PSEN1dE9)85Dbo/J mice]. == Experimental Procedures == == Mice anesthesia == Mice were used to 4-hydroxyephedrine hydrochloride assess the potential in vivo effects of isoflurane on levels of proinflammatory cytokines. The protocol was approved by the Massachusetts General Hospital Standing Committee on Animals (Boston, Massachusetts) on the Use of Animals in Research and Teaching. Wild type mice (C57BL/6 mice) and AD transgenic mice [B6.Cg-Tg (APPswe, PSEN1dE9)85Dbo/J mice] (Jackson Laboratory, Bar Harbor, ME) at 5-8 months aged were randomized by excess weight and gender into either an experimental group that received 1.4% isoflurane (a clinically relevant concentration) plus 100% oxygen for two hours or a control group that received 100% oxygen for two hours at an identical flow rate in identical anesthetizing chambers Tnfrsf10b as previously explained (Xie et al., 2008). We selected this anesthesia because the anesthesia with 2% isoflurane plus 100% oxygen for two hours is usually clinically relevant and has been shown to induce caspase activation and increase levels of BACE and A without significant changes in blood pressure and blood gas in the mice at 5-8 month aged (Xie et al., 2008). Moreover, the AD transgenic mice used in the experiment usually start to develop elevated A levels during this age range (Garcia-Alloza et al., 2006). The mice breathed spontaneously, and the concentrations of isoflurane and oxygen were measured constantly (Datex, Tewksbury, MA). The heat of the anesthetizing chamber was controlled to maintain rectal heat of mice at 37 0.5C. Anesthesia was terminated by discontinuing isoflurane and placing animals in a chamber made up of 100% oxygen until 4-hydroxyephedrine hydrochloride 20 moments after the return of their righting reflex. They were then returned to individual home cages until they were humanely killed. == Main neurons == Main neurons were used to assess the potential in vitro effects of isoflurane on levels of proinflammatory cytokines. Wild type mice and AD 4-hydroxyephedrine hydrochloride transgenic mice with a gestation stage of day 15 were killed with carbon dioxide. We then performed a cesarean section to.
Cytochrome P450