Referenced in: none

Automatically associated channels: Cav1.2

Title: The local anesthetic butamben inhibits total and L-type barium currents in PC12 cells.

Authors: Laurentius J A Rampaart, Jeroen P Beekwilder, Gertrudis Th H van Kempen, Rutgeris J van den Berg, Dirk L Ypey

Journal, date & volume: Anesth. Analg., 2008 Jun , 106, 1778-83

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/18499609

Abstract
Butamben or n-butyl-p-aminobenzoate is a long-acting experimental local anesthetic for the treatment of chronic pain when given as an epidural suspension. We have investigated whether Cav1.2/L-type calcium channels may be a target of this butamben action.The effect of butamben on these channels was studied in undifferentiated rat PC12-cells with the whole-cell patch-clamp technique in voltage-clamp. Ba(2+) ions were used as the charge carriers in the calcium channel currents, whereas K(+) currents were removed using K(+) free solutions.Butamben 500 microM reversibly suppressed the total whole-cell barium current by 90% +/- 3% (n = 15), whereas 10 microM nifedipine suppressed this barium current by 75% +/- 7% (n = 6). Preexposure to butamben followed by washout decreased the inhibition by nifidepine to 47% +/- 5% (n = 10). These suppressive effects were not due to the measurement procedure and the drug vehicles in the solutions (<0.1% ethanol; n = 6).Butamben inhibits the total barium current through expressed calcium channel types in PC12 cells, including Cav1.2/L-type channels. Because Cav1.2 channels may also occur in human nociceptive C fibers, this result allows the possibility that these L-type channels are involved in the analgesic action of butamben.