Title

Propofol Modulates Agonist-Induced Transient Receptor Potential Vanilloid Subtype-1 Receptor Desensitization Via a Protein Kinase Cε-dependent Pathway in Mouse Dorsal Root Ganglion Sensor

Publication Title

Anesthesiology

Publication Date

10-2010

Document Type

Article

DOI

10.1097/ALN.0b013e3181eaa9a0

Disciplines

Anesthesiology

Abstract

Background

The activity of transient receptor potential vanilloid subtype-1 (TRPV1) receptors, key nociceptive transducers in dorsal root ganglion sensory neurons, is enhanced by protein kinase C ε (PKCε) activation. The intravenous anesthetic propofol has been shown to activate PKCε. Our objectives were to examine whether propofol modulates TRPV1 function in dorsal root ganglion neuronsvia activation of PKCε.

Methods

Lumbar dorsal root ganglion neurons from wild-type and PKCε-null mice were isolated and cultured for 24 h. Intracellular free Ca2+ concentration was measured in neurons by using fura-2 acetoxymethyl ester. The duration of pain-associated behaviors was also assessed. Phosphorylation of PKCε and TRPV1 and the cellular translocation of PKCε from cytosol to membrane compartments were assessed by immunoblot analysis.

Results

In wild-type neurons, repeated stimulation with capsaicin (100 nM) progressively decreased the transient rise in intracellular free Ca2+ concentration. After desensitization, exposure to propofol rescued the Ca2+ response. The resensitizing effect of propofol was absent in neurons obtained from PKCε-null mice. Moreover, the capsaicin-induced desensitization of TRPV1 was markedly attenuated in the presence of propofol in neurons from wild-type mice but not in neurons from PKCε-null mice. Propofol also prolonged the duration of agonist-induced pain associated behaviors in wild-type mice. In addition, propofol increased phosphorylation of PKCε as well as TRPV1 and stimulated translocation of PKCε from cytosolic to membrane fraction.

Discussion

Our results indicate that propofol modulates TRPV1 sensitivity to capsaicin and that this most likely occurs through a PKCε-mediated phosphorylation of TRPV1.

This document is currently not available here.


Share

COinS