Anesthesia and analgesia
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Anesthesia and analgesia · Dec 2011
Comparative StudyMutated p.4894 RyR1 function related to malignant hyperthermia and congenital neuromuscular disease with uniform type 1 fiber (CNMDU1).
Ryanodine receptor 1 (RyR1) is a Ca(2+) release channel located in the sarcoplasmic reticulum membrane of skeletal muscle. More than 200 variants in RyR1 have been identified in DNA from patients with malignant hyperthermia (MH) and congenital myopathies; only 30 have been sufficiently studied so as to be identified as MH-causative mutations. The Ala4894Thr RyR1 variant was found in a Japanese patient with susceptibility to MH, and the Ala4894Pro variant in a rare case of myopathy: congenital neuromuscular disease with uniform type 1 fiber (CNMDU1). We hypothesized that different Ala4894 variants of RyR1 cause different pathophysiological changes that are identifiable by having differing pharmacological sensitivities to RYR1 agonists. ⋯ We concluded that different Ala4894 variants of RyR1 lead to different agonist/antagonist sensitivities, which may predict differing RYR1 functionality during excitation-contraction coupling and sensitivity to MH. The hypersensitive Ala4894Thr-RyR1 is associated with MH and the poorly functional Ala4894Pro-RyR1 with CNMDU1.
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Anesthesia and analgesia · Dec 2011
Comparative StudyIntrathecal ultra-low dose naloxone enhances the antinociceptive effect of morphine by enhancing the reuptake of excitatory amino acids from the synaptic cleft in the spinal cord of partial sciatic nerve-transected rats.
In this study, we examined the effects of ultra-low dose naloxone on the antinociceptive effect of morphine and on spinal cord dorsal horn glutamate transporter expression in rats with neuropathic pain. ⋯ Ultra-low dose naloxone enhanced the antinociceptive effect of morphine in PST rats, possibly by restoration of GLAST and GLT-1 expression in astrocytes, which inhibited the accumulation of EAAs in the synapses, resulting in a neuroprotective effect.
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Anesthesia and analgesia · Dec 2011
Comparative StudyMolecular mechanisms of the inhibitory effects of clonidine on vascular adenosine triphosphate-sensitive potassium channels.
We investigated the effects of the imidazoline-derived α2-adrenoceptor agonist clonidine on vascular adenosine triphosphate-sensitive potassium (K(ATP)) channel activity in rat vascular smooth muscle cells and recombinant vascular K(ATP) channels transiently expressed in COS-7 cells. ⋯ Clinically relevant concentrations of clonidine inhibit K(ATP) channel activity in vascular smooth muscle cells. This inhibition seems to be the result of its effect on the Kir6.0 subunit and not on the SUR subunit.
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Anesthesia and analgesia · Dec 2011
Comparative StudyIsoflurane anesthesia preserves liver and lung mitochondrial oxidative capacity after gut ischemia-reperfusion.
Lung and liver dysfunction is involved in gut ischemia-reperfusion (IR)-induced multiple organ failure. We compared the effects of ketamine and isoflurane on liver and lung mitochondrial oxidative capacity after gut IR. ⋯ Isoflurane preserved liver and lung mitochondrial oxidative capacity after gut IR.