Calcium channels play important roles in cellular signalling. TRP (transient receptor potential) channels form a superfamily of calcium channels through which Ca(2+) enters the cell. TRPs have six transmembrane segments with a putative pore between the fifth and the sixth segments, and assemble in tetrameric complexes to form functional Ca(2+) channels. They are thus similar to K(V) (voltage-ga...

The effects of an intravenous capsaicin challenge on the respiratory pattern and ventilation were studied in 15 urethane/chloralose-anaesthetized, spontaneously breathing rats. Bolus injection of capsaicin at a dose of 5 micrograms/kg into the right femoral vein evoked respiratory arrest in all animals (both prior to and after bilateral midcervical vagotomy), which effect was abolished by ruthe...

To investigate the effects of loss of transient receptor potential vanilloid receptor 1 (TRPV1) on the development of neovascularization in corneal stroma in mice. Blocking TRPV1 receptor did not affect VEGF-dependent neovascularization in cell culture. Lacking TRPV1 inhibited neovascularization in corneal stroma following cauterization. Immunohistochemistry showed that immunoreactivity for act...

INTRODUCTION Previous studies have shown that the cannabinoid system is involved in anxiety. In addition, transient receptor potential vanilloid type-1 (TRPV1) channels are new targets for the development of anxiolytics. The present study investigated the possible interaction between the cannabinoid and vanilloid systems on anxiety-like behavior in rats. METHODS Four different groups of male ...

Capsaicin (CAP)-activated ion channel plays a key role in generating nociceptive neural signals in sensory neurons. Here we present evidence that intracellular ATP upregulates the activity of capsaicin receptor channel. In inside-out membrane patches isolated from sensory neurons, application of CAP activated a nonselective cation channel (i(cap)). Further addition of ATP to the bath caused a s...

This study was designed to test the hypothesis that increased sensitivity of blood pressure to anandamide (AEA), an endocannabinoid compound, occurs during high-salt intake, which can be blocked by a selective vanilloid receptor 1(VR1) antagonist, capsazepine (CAPZ). Intravenous administration of a metabolically stable analog, methanandamide (MethA), dose-dependently decreased mean arterial pre...

To study the acute and long-term effects of local gut inflammation on the sensitivity of the spinal sensory neurons, the expressions of vanilloid receptor 1 (VR1) and calcitonin gene-related peptide (CGRP) in the colon-innervated primary sensory neurons in dorsal root ganglia (DRG) were examined in rats with trinitrobenzenesulfonic acid (TNBS)-induced experimental colitis. The neurons projectin...

The recently cloned vanilloid receptor subtype 1 (VR1) is a ligand-gated channel that is activated by capsaicin, protons, and heat. We have attempted to develop a dominant negative isoform by targeting several mutations of VR1 at highly conserved amino acids or at residues of potential functional importance and expressing the mutants in Chinese hamster ovary cells. Mutation of three highly cons...

Recently, with use of rat dorsal root ganglion (DRG) neurons we have been able to dissociate the binding affinities of vanilloids from their potencies to induce 45Ca uptake, which suggests the existence of distinct classes of the vanilloid receptor (). In the present study, we have demonstrated that the ultrapotent capsaicin analog resiniferatoxin (RTX) desensitized rat DRG neurons to the subse...