Skip to main content
. 2017 May;139(5):e20161560. doi: 10.1542/peds.2016-1560

FIGURE 3.

FIGURE 3. High concentrations of carbamazepine 10,11-epoxide (CBZ-10-11 epoxide) lead to acute mitochondrial hyperpolarization in cultured neurons in vitro. On day in vitro 18 to 21, cultured rat cortical neurons28 were loaded with the potentiometric cell–permeable fluorescent probe TMRE (tetramethylrhodamine, ethyl ester); its fluorescence on live cell confocal microscopy is known to correlate with mitochondrial membrane potential (ΔΨm).29 A, After 5 minutes to acquire a set of baseline images (top panels), drugs were applied at the indicated concentrations (lower panels). CBZ-10-11 epoxide was used because it is the main active metabolite of carbamazepine.30 B, TMRE fluorescence intensity was measured and is expressed as ΔF (percent change in fluorescence from baseline). This change in fluorescence intensity reflects the changes in ΔΨm.29 CBZ-10-11 epoxide significantly increased the TMRE signal, indicating hyperpolarized ΔΨm. Standard assay calibration was performed by using oligomycin (an adenosine triphosphate synthase inhibitor), which led to a transient hyperpolarization followed by depolarization, and antimycin A (a mitochondrial electron transport inhibitor), which strongly depolarized the membrane. ****P < .0001 (analysis of variance with Bonferroni's multiple comparison test; compared with vehicle). Data are presented as mean ± SD.

High concentrations of carbamazepine 10,11-epoxide (CBZ-10-11 epoxide) lead to acute mitochondrial hyperpolarization in cultured neurons in vitro. On day in vitro 18 to 21, cultured rat cortical neurons28 were loaded with the potentiometric cell–permeable fluorescent probe TMRE (tetramethylrhodamine, ethyl ester); its fluorescence on live cell confocal microscopy is known to correlate with mitochondrial membrane potential (ΔΨm).29 A, After 5 minutes to acquire a set of baseline images (top panels), drugs were applied at the indicated concentrations (lower panels). CBZ-10-11 epoxide was used because it is the main active metabolite of carbamazepine.30 B, TMRE fluorescence intensity was measured and is expressed as ΔF (percent change in fluorescence from baseline). This change in fluorescence intensity reflects the changes in ΔΨm.29 CBZ-10-11 epoxide significantly increased the TMRE signal, indicating hyperpolarized ΔΨm. Standard assay calibration was performed by using oligomycin (an adenosine triphosphate synthase inhibitor), which led to a transient hyperpolarization followed by depolarization, and antimycin A (a mitochondrial electron transport inhibitor), which strongly depolarized the membrane. ****P < .0001 (analysis of variance with Bonferroni's multiple comparison test; compared with vehicle). Data are presented as mean ± SD.