Effects of bupivacaine on human erythrocytes submitted to stress and evidence for an interaction between bupivacaine and flumazenil.
OBJECTIVE
To examine the effects of bupivacaine on erythrocytes submitted to an oxidative stress (AAPH) and to provide evidence for an in vitro interaction between bupivacaine and flumazenil.


METHODS
Human erythrocytes were studied with or without AAPH in the presence of different concentrations of bupivacaine (0.15, 0.3, 0.9 and 1.8 mmol l-1 ), or flumazenil (0.16 mmol l-1 ) and with the association of flumazenil and two doses of bupivacaine (0.15 and 0.3 mmol l-1 ). Potassium efflux was measured by flame photometry at T0, and every 30 min for 2 h.


RESULTS
In the absence of AAPH, extracellular potassium remained unchanged. Oxidative stress induced a significant increase in extracellular potassium, which was not modified by incubation with flumazenil. Bupivacaine significantly lowered the increase in extracellular potassium in a dose-related fashion. The association with flumazenil blunted the effects of bupivacaine. Discussion In this model, bupivacaine proved effective in protecting erythrocytes against oxidative stress. Flumazenil interacted with bupivacaine and blunted its protective effects.
Lenfant
F
F
Laboratoire de Physiopathologie et Pharmacologie Cardiovasculaires Expérimentales, Facultés de Médecine et de Pharmacie de l'Université de Bourgogne, Dijon, France.
Lahet
J J
JJ
Volot
F
F
Schafer
I
I
Freysz
M
M
Rochette
L
L
D000779:Anesthetics, Local / Q000494:pharmacology*; D000931:Antidotes / Q000494:pharmacology*; D002045:Bupivacaine / Q000494:pharmacology*; D004347:Drug Interactions; D004912:Erythrocytes / Q000187:drug effects* / Q000378:metabolism; D005442:Flumazenil / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D018384:Oxidative Stress; D011188:Potassium / Q000378:metabolism
D000779:Anesthetics, Local; D000931:Antidotes; D005442:Flumazenil; D011188:Potassium; D002045:Bupivacaine