INVESTIGADORES
MILESI Maria Veronica
artículos
Título:
Bupivacaine inhibits large conductance, voltage- and Ca ( 2+) - activated K (+) channels in human umbilical artery smooth muscle cells.
Autor/es:
MARTIN PEDRO; ENRIQUE NICOLAS; ROLDAN PALOMO ANA ROCIO; REBOLLEDO ALEJANDRO; MILESI VERONICA
Revista:
CHANNELS
Editorial:
LANDES BIOSCIENCE
Referencias:
Lugar: Austin, Texas; Año: 2012 vol. 6 p. 174 - 180
ISSN:
1933-6950
Resumen:
Bupivacaine is a local anesthetic compound belonging to the amino amide group. Its anesthetic effect is commonly related to its inhibitory effect on voltage-gated sodium channels. However, several studies have shown that this drug can also inhibit voltage-operated K (+) channels by a different blocking mechanism. This could explain the observed contractile effects of bupivacaine on blood vessels. Up to now, there were no previous reports in the literature about bupivacaine effects on large conductance voltage- and Ca ( 2+) -activated K (+) channels (BKCa). Using the patch-clamp technique, it is shown that bupivacaine inhibits single-channel and whole-cell K (+) currents carried by BKCa channels in smooth muscle cells isolated from human umbilical artery (HUA). At the single-channel level bupivacaine produced, in a concentration- and voltage-dependent manner (IC 50 324 µM at +80 mV), a reduction of single-channel current amplitude and induced a flickery mode of the open channel state. Bupivacaine (300 µM) can also block whole-cell K (+) currents (~45% blockage) in which, under our working conditions, BKCa is the main component. This study presents a new inhibitory effect of bupivacaine on an ion channel involved in different cell functions. Hence, the inhibitory effect of bupivacaine on BKCa channel activity could affect different physiological functions where these channels are involved. Since bupivacaine is commonly used during labor and delivery, its effects on umbilical arteries, where this channel is highly expressed, should be taken into account.