Allosteric interaction of the neuromuscular blockers vecuronium and pancuronium with recombinant human muscarinic M2 receptors.

Neuromuscular blocking drugs produce muscle weakness by interaction with nicotinic-acetylcholine receptors. Cardiovascular side effects have been reported. In this study the neuromuscular blocking drug vecuronium and the controls gallamine and pancuronium slowed the rate of atropine induced [(3)H]N-methylscopolamine dissociation from Chinese hamster ovary cells expressing recombinant human muscarinic M2 receptors K(off) values min(-1); vecuronium (125 nM), atropine 0.

Nerve blocks (subcostal, lateral cutaneous, femoral, triple, psoas) for hip fractures.

Background: Various nerve blocks using local anaesthetic agents have been used in order to reduce pain after hip fracture.

Objectives: To determine the effects of nerve blocks (inserted either pre-operatively, operatively or post-operatively) as part of the treatment for a hip fracture.

Search Strategy: We searched the Cochrane Musculoskeletal Injuries Group specialised register (October 2001), MEDLINE -OVID WEB (1996 to October 2001) and reference lists of relevant articles.

Nerve blocks (subcostal, lateral cutaneous, femoral, triple, psoas) for hip fractures.

Background: Various nerve blocks using local anaesthetic agents have been used in order to reduce pain after hip fracture.

Objectives: To determine the effects of nerve blocks (inserted either pre-operatively, operatively or post-operatively) as part of the treatment for a hip fracture.

Search Strategy: The Cochrane Musculoskeletal Injuries Group specialised trials register, MEDLINE, and bibliographies of trial reports were searched.

Nerve blocks (subcostal, lateral cutaneous, femoral, triple, psoas) for hip fractures.

Background: Various nerve blocks using local anaesthetic agents have been used in order to reduce pain after hip fracture.

Objectives: To determine the effects of nerve blocks (inserted either pre-operatively, operatively or post-operatively) as part of the treatment for a hip fracture.

Search Strategy: The Cochrane Musculoskeletal Injuries Group specialised trials register, MEDLINE, and bibliographies of trial reports were searched.

Interaction of local anaesthetics with recombinant mu, kappa, and delta-opioid receptors expressed in Chinese hamster ovary cells.

Local anaesthetics potentiate epidural or intrathecal opioid analgesia via a poorly defined mechanism. In this study, we have examined the interaction of local anaesthetics (lidocaine, bupivacaine and its optical isomers, tetracaine, procaine and prilocaine) with recombinant mu-, kappa-, and delta-opioid receptors expressed in Chinese hamster ovary cells (CHO-mu, kappa, and delta, respectively). Lidocaine produced a concentration-dependent displacement of radiolabelled opioid antagonist [3H]diprenorphine ([3H]DPN) binding with the following rank order of inhibitor constant (Ki): kappa (210 microM) > mu (552 microM) > delta (1810 microM).

Nerve blocks (subcostal, lateral cutaneous, femoral, triple, psoas) for hip fractures.

Background: Various nerve blocks using local anaesthetic agents have been used in order to reduce pain after hip fracture.

Objectives: To determine the effects of nerve blocks (inserted either pre-operatively, operatively or post-operatively) as part of the treatment for a hip fracture.

Search Strategy: The Cochrane Musculoskeletal Injuries Group trials register, MEDLINE, and bibliographies of trial reports were searched.

Stereoselective interaction of ketamine with recombinant mu, kappa, and delta opioid receptors expressed in Chinese hamster ovary cells.

Background: The authors examined the interaction of ketamine with recombinant mu, kappa, and delta opioid receptors and recombinant orphan opioid receptors expressed in Chinese hamster ovary cells (CHO-mu, CHO-kappa, CHO-delta, and CHO(ORL1), respectively).

Methods: CHO-mu, CHO-kappa, and CHO-delta membranes were incubated with the opioid receptor radioligand [3H]diprenorphine at room temperature. Ketamine (racemic, R(-) and S(+)) was included at concentrations covering the clinical range.

Interaction of neuromuscular blocking drugs with recombinant human m1-m5 muscarinic receptors expressed in Chinese hamster ovary cells.

1. Neuromuscular blocking drugs (NMBD's) are known to produce cardiovascular side effects manifesting as brady/tachycardias. In this study we have examined the interaction of a range of steroidal NMBD's with recombinant human m1-m5 muscarinic receptors expressed in Chinese hamster ovary cells.

Anaesthetic potency of inhalation agents is independent of membrane microviscosity.

The decrease in membrane microviscosity of erythrocyte ghosts in the presence of clinically relevant concentrations of seven inhalation anaesthetic agents was studied using fluorescence polarization anisotropy of the membrane incorporated fluorescent probes 1,6-diphenyl-1,3,5-hexatriene and 1-[4-trimethylammoniumphenyl]-6-phenyl-1,3,5-hexatriene. All anaesthetic agents produced a dose-dependent decrease in anisotropy of both probes, indicating decreased membrane microviscosity. The reduction in anisotropy measured at the minimum alveolar concentration (ED50) for anaesthesia was related inversely to the anaesthetic potency of the agent and was directly proportional to the hypothetical concentration of agent in the membrane calculated from lipid-water partition coefficients.

Do local anaesthetics interact with dihydropyridine binding sites on neuronal L-type Ca2+ channels?

We have examined the interaction of procaine, prilocaine, lignocaine, bupivacaine, amylocaine and R(+) and S(-) ropivacaine with L-type voltage-sensitive Ca2+ channels in rat cerebrocortical membranes. Membranes were prepared in Tris HCl 50 mmol litre-1, pH 7.4, by homogenization and centrifugation.

Postal survey on the long-term use of neuromuscular block in the intensive care.

Objective: To assess the long-term use of neuromuscular blocking (NMB) agents in intensive care, especially with reference to the potential problems of the long-term use of NMB drugs in the intensive care unit (ICU).

Method: A postal survey questionnaire was sent to 409 ICUs in Great Britain.

Results: Two hundred thirty-eight completed questionnaires were returned and analysed.

Dose requirements, efficacy and side effects of morphine and pethidine delivered by patient-controlled analgesia after gynaecological surgery.

We have compared the dose requirements and side effects of morphine with those of pethidine when administered by patient-controlled analgesia in 40 patients (ASA I-II, 20-65 yr) after elective total abdominal hysterectomy. Patients were allocated randomly, in a double-blind manner, to receive either morphine (bolus dose 2 mg, lockout time 10 min) or pethidine (bolus dose 20 mg, lockout time 10 min) for postoperative pain relief. Mean 24-h morphine and pethidine consumption was 70 (SEM 6.

Interaction of i.v. anaesthetic agents with 5-HT3 receptors.

Using N1E-115 neuroblastoma cells as an experimental model, we have examined if four commonly used i.v. anaesthetic induction agents interact with 5-HT3 receptors.

Studies on the interaction of steroidal neuromuscular blocking drugs with cardiac muscarinic receptors.

Interaction of the steroidal neuromuscular blocking drugs pancuronium, pipecuronium, rocuronium and vecuronium with cardiac muscarinic receptors in rat hearts was investigated in vitro by a tritiated N-methyl hyoscine binding assay. We showed an interaction with cardiac muscarinic receptors with a rank order of potency pancuronium > vecuronium > pipecuronium > rocuronium and demonstrated complex binding characteristics for pancuronium, vecuronium and rocuronium, with "Hill coefficient" of less than unity. We conclude that the haemodynamic differences seen during the use of these neuromuscular blocking drugs may be a result of their interactions with cardiac M2 muscarinic receptors.