S(+)-ketamine suppresses desensitization of γ-aminobutyric acid type B receptor-mediated signaling by inhibition of the interaction of γ-aminobutyric acid type B receptors with G protein-coupled receptor kinase 4 or 5.

Background: Intrathecal baclofen therapy is an established treatment for severe spasticity. However, long-term management occasionally results in the development of tolerance. One of the mechanisms of tolerance is desensitization of γ-aminobutyric acid type B receptor (GABABR) because of the complex formation of the GABAB2 subunit (GB2R) and G protein-coupled receptor kinase (GRK) 4 or 5.

Presence of GABA(B) receptors forming heterodimers with GABA(B1) and GABA(B2) subunits in human lower esophageal sphincter.

Baclofen, a GABA(B)-receptor (GABA(B)R) agonist has been proposed to be useful as therapeutic agent for the management of gastro-esophageal reflux disease, but whether the compound acts directly at the lower esophageal sphincter (LES) remains to be elucidated. We performed the present study to assess the presence of GABA(B)R in human LES. Western blot analysis showed that both proteins of GABA(B1(a))/GABA(B1(b)) and GABA(B2) subunits were present in the muscle layer of LES.

mu-Opioid receptor forms a functional heterodimer with cannabinoid CB1 receptor: electrophysiological and FRET assay analysis.

Interactions between mu-opioid receptor (muOR) and cannabinoid CB1 receptor (CB1R) were examined by morphological and electrophysiological methods. In baby hamster kidney (BHK) cells coexpressing muOR fused to the yellow fluorescent protein Venus and CB1R fused to the cyan fluorescent protein Cerulean, both colors were detected on the cell surface; and fluorescence resonance energy transfer (FRET) analysis revealed that muOR and CB1R formed a heterodimer. Coimmunoprecipitation and Western blotting analyses also confirmed the heterodimers of muOR and CB1R.

The effect of sevoflurane-induced hypotension in combination with acute hypervolaemic haemodilution on middle cerebral artery flow velocity in surgical patients.

Background And Objective: This study was carried out to clarify the effect of the combination of acute hypervolaemic haemodilution and hypotensive anaesthesia induced with sevoflurane on human middle cerebral artery flow velocity using transcranial Doppler ultrasonography.

Methods: Thirty patients who were maintained with N2O-O2-sevoflurane anaesthesia undergoing hip surgery were randomly divided into two groups (no controlled hypotension group, Group A, and controlled hypotension group, Group B). Haemodilution was produced by acute preoperative infusion of 1000 mL of hydroxyethylstarch without removing blood in both groups.