Isoflurane activates human cardiac mitochondrial adenosine triphosphate-sensitive K+ channels reconstituted in lipid bilayers.

Background: Activation of the mitochondrial adenosine triphosphate (ATP)-sensitive K+ channel (mitoK(ATP)) has been proposed as a critical step in myocardial protection by isoflurane-induced preconditioning in humans and animals. Recent evidence suggests that reactive oxygen species (ROS) may mediate isoflurane-mediated myocardial protection. In this study, we examined the direct effect of isoflurane and ROS on human cardiac mitoK(ATP) channels reconstituted into the lipid bilayers.

Characterization of human cardiac mitochondrial ATP-sensitive potassium channel and its regulation by phorbol ester in vitro.

Activation of the mitochondrial ATP-sensitive K+ channel (mitoKATP) and its regulation by PKC are critical events in preconditioning induced by ischemia or pharmaceutical agents in animals and humans. The properties of the human cardiac mitoKATP channel are unknown. Furthermore, there is no evidence that cytosolic PKC can directly regulate the mitoKATP channel located in the inner mitochondrial membrane (IMM) due to the physical barrier of the outer mitochondrial membrane.

Intracellular mechanism of mitochondrial adenosine triphosphate-sensitive potassium channel activation with isoflurane.

Unlabelled: The precise mechanism of isoflurane and mitochondrial adenosine triphosphate-sensitive potassium channel (mitoK(ATP)) interaction is still unclear, although the mitoK(ATP) is involved in isoflurane-induced preconditioning. We examined the role of various intracellular signaling systems in mitoK(ATP) activation with isoflurane. Mitochondrial flavoprotein fluorescence (MFF) was measured to quantify mitoK(ATP) activity in guinea pig cardiomyocytes.

Modulation of myofilament Ca2+ densitivity by delta- and kappa-opioid agonists in intact guinea pig hearts.

Unlabelled: We investigated whether delta- and kappa-opioid agonists alter myocardial function, intracellular Ca(2+) concentration ([Ca(2+)](i)), and myofilament Ca(2+) sensitivity in intact guinea pig beating hearts and whether these effects are mediated by an opioid receptor. Intact guinea pig hearts were perfused with modified Krebs Ringer solution containing delta- (TAN-67) and kappa- (ICI-199441) opioid agonists in the absence and presence of delta- (BNTX) and kappa- (nor-BNI) opioid antagonists, respectively, while functional variables and [Ca(2+)](i) were recorded. TAN-67 (1 microM) and ICI-199441 (1 microM) decreased heart rate (P < 0.

Isoflurane activates rat mitochondrial ATP-sensitive K+ channels reconstituted in lipid bilayers.

Activation of mitochondrial ATP-sensitive K(+) (mitoK(ATP)) channels is critical in myocardial protection induced by preconditioning with volatile anesthetics or brief periods of ischemia. In this study, we characterized rat mitoK(ATP) channels reconstituted in lipid bilayers and examined their direct regulation by isoflurane. Mitochondria and the inner membrane fraction were isolated from rat ventricles and fused into lipid bilayers.

Humidification during low-flow anesthesia in children.

Purpose: The aim of this study was to compare the effect of low-flow anesthesia with or without a heat and moisture exchanger with high-flow anesthesia on airway gas humidification in children.

Methods: One hundred twenty children were randomly assigned to one of three groups: low-flow anesthesia with 0.5l·min of total gas flow (LFA,n=40), low-flow anesthesia with 0.