Effects of 12, 13 dibutyrate (PDBu) on resting and capsaicin-stimulated glutamate release in adult rat dorsal root neurons in culture

Abstract

This investigation explored the role of PKC as an activator of VR1 through the use of capsaicin, a natural ligand for VR1, and the PKC activating phorbol ester 12,13 dibutyrate (PDBu). Direct effects of 30nM, 300nM, and 3000nM capsaicin and 0nM, 0.3nM, 1.0nM, 3.0nM, 10nM, and 30nM PDBu on glutamate release from adult rat dorsal root ganglia (DRGs) were examined. Based on those observations, the concentration of capsaicin causing the least glutamate release and the concentrations of PDBu that did not elicit significant glutamate release were selected to study effects of capsaicin on same cell type acutely sensitized with the selected concentrations of PDBu. It was found that glutamate released from combinations of 30nM capsaicin and 1.0nM PDBu (p<0.036) as well as 30nM capsaicin and 3.0nM PDBu (p<0.01) were statistically significant from the stimulation control—which was 30nM capsaicin alone.