Cytometric analysis of lidocaine-induced cytotoxicity: a model experiment using rat thymocytes.
Lidocaine is a local anesthetic possessing both lipophilic and hydrophilic properties. It also acts as a surfactant. Thus, the disruption of membranes, resulting in necrosis, is one of possible mechanisms for lidocaine-induced cytotoxicity. However, lidocaine is reported to induce apoptosis. Therefore, in order to compare two mechanisms for cell death induced by lidocaine, the effects of millimolar lidocaine were examined on rat thymocytes by a flow cytometer with appropriate fluorescent probes. Lidocaine decreased the population of living cells with phosphatidylserine-exposed membranes, one of markers for early stage of apoptosis, and increased the population of dead cells without increasing that of cells with hypodiploidal DNA. Lidocaine at millimolar concentrations may deteriorate the membranes of such apoptotic living cells rather than those of intact living cells, resulting in necrosis. It is suggested that the process of apoptosis is not completed in the presence of millimolar lidocaine.
Nishimura
Yumiko
Y
Laboratory of Cellular Signaling, Faculty of Integrated Arts and Sciences, The University of Tokushima, Tokushima 770-8502, Japan.
Kanada
Aimi
A
Yamaguchi
Jun-ya
JY
Horimoto
Kanna
K
Kobayashi
Masako
M
Tatsuishi
Tomoko
T
Kanemaru
Kaori
K
Ueno
Shin-ya
SY
Oyama
Yasuo
Y
D000779:Anesthetics, Local / Q000009:adverse effects*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D048429:Cell Size / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D005434:Flow Cytometry; D008012:Lidocaine / Q000009:adverse effects*; D008297:Male; D008954:Models, Biological; D051381:Rats; D017208:Rats, Wistar; D013950:Thymus Gland / Q000187:drug effects / Q000473:pathology*
D000779:Anesthetics, Local; D008012:Lidocaine