Only tetracaine and not other local anaesthetics induce apoptosis in rat cortical astrocytes.
BACKGROUND
The potential risks of neurotoxicity due to local anaesthetics after regional anaesthesia have been suggested recently. To evaluate the neurotoxicity of commonly used local anaesthetics, primary cultured rat cortical astrocytes were treated with lidocaine, ropivacaine, bupivacaine, levobupivacaine, and tetracaine.


METHODS
Cell death after local anaesthetic treatment was evaluated with a lactate dehydrogenase (LDH) assay. To examine the mechanisms of cell death, reactive oxygen species (ROS) measurement and western blots of poly-ADP ribose polymerase (PARP), procaspase-3, and mitogen-activated protein kinases family members were performed.


RESULTS
Of the local anaesthetics, which were applied at <1 mM for 18 h, only tetracaine significantly increased LDH leakage (P<0.05) and cell death in a dose- and time-dependent manner. Hoechst 33258-propidium iodide staining and western blots with PARP and procaspase-3 antibodies suggested that tetracaine induced apoptosis. ROS levels increased 2-fold at 30 min after tetracaine treatment compared with the control and then decreased. The antioxidants, N-acetylcysteine and trolox, markedly inhibited tetracaine-induced apoptosis.


CONCLUSIONS
Tetracaine induced apoptosis through ROS generation. Further studies focusing on the neurotoxicity of tetracaine are needed.
Lee
W Y
WY
Department of Dental Anesthesiology and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea.
Park
C J
CJ
Shin
T J
TJ
Yum
K W
KW
Yoon
T G
TG
Seo
K S
KS
Kim
H J
HJ
D000779:Anesthetics, Local / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001253:Astrocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D048430:Cell Shape / Q000187:drug effects; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D013748:Tetracaine / Q000494:pharmacology*
D000779:Anesthetics, Local; D017382:Reactive Oxygen Species; D013748:Tetracaine