Isoflurane Activates Sarcolemmal Adenosine Triphosphate-sensitive Potassium Channels in Vascular Smooth Muscle Cells

Abstract

These results indicate that isoflurane activates K(ATP) channels via PKA activation. PKA-dependent vasodilation induced by isoflurane also was observed in isometric tension experiments. Analysis of expressed vascular-type K(ATP) channels suggested that PKA-mediated phosphorylation of both Kir6.1 and SUR2B subunits plays a pivotal role in isoflurane-induced vascular K(ATP) channel activation.

Differential effects of propofol and isoflurane on glucose utilization and insulin secretion

“…activate K ATP channels not only in pancreatic β cells, but also in cardiac myocytes (Fujimoto et al, 2002) and vascular smooth muscle cells (Tanaka et al, 2007). It has been reported that volatile anesthetics have cardioprotective and vasodilative effects mediated by activation of cardiac (Tanaka et al, 2003(Tanaka et al, , 2004 and vascular K ATP channels (Tanaka et al, 2007), respectively. The present results indicate that isoflurane impairs glucose tolerance and insulin secretion via activation of pancreatic K ATP channels.…”

Functional roles of ATP-sensitive potassium channel as related to anesthesia

“…In vivo studies on canines show that vascular K ATP -channel activation is also involved in coronary vasodilatation induced by volatile anesthetics [21]. Furthermore, we reported electrophysiological experiments in rats, which revealed isofluraneinduced K ATP -channel activation via direct phosphorylation of a cyclic adenosine monophosphate (cAMP)-dependent protein kinase (protein kinase A) [22]. These results indicated that isoflurane-induced coronary vasodilatation is mediated by vascular K ATP -channel opening.…”

L-DOPA inhibits nitric oxide-dependent vasorelaxation via production of reactive oxygen species in rat aorta

“…Rocchitta et al (25) reported that autooxidation of exogenous L-DOPA occurs in vivo in the extracellular compartment of the freely moving rat with a consequent formation of L-DOPA semiquinone (L-DOPA-SQ) in dialysates. NO reacting with superoxide generates peroxynitrite (O=NOO -) to block NO signaling pathway by inactivating NO (20,26,27), leading to decrease of ring relaxation (12,13). L-DOPA is transported into mammalian cells through the L-type amino acid transporter 1 (LAT1) (13), which is also expressed in vascular endothelium (28).…”

“…NO reacting with superoxide generates peroxynitrite (O=NOO -) to block NO signaling pathway by inactivating NO (20,26,27), leading to decrease of ring relaxation (12,13). L-DOPA is transported into mammalian cells through the L-type amino acid transporter 1 (LAT1) (13), which is also expressed in vascular endothelium (28). In vitro experiments showed that L-DOPA can lead to accumulation of O2 -, and the addition of SOD resulted in higher levels of NO2…”

“…Isolation of vascular smooth muscle cells from rats was conducted as described previously (13). Briefly, male Wistar rats aged 8 to 10 weeks were anesthetized with ether, and 1.0 U/g heparin was injected into the peritoneal cavity 30 min before surgery.…”