Fluo 8 acetoxymethyl ester fluo 8 am

(1S,2S)-2-[2-[[3-(1H-Benzimidazol-2-yl)propyl]methylamino]ethyl]-6-fluoro-1,2,3,4-tetrahydro-1-(1-methylethyl)-2-naphthalenyl methoxyacetate dihydrochloride (mibefradil; a T-type VGCC blocker) was purchased from Cayman Chemical Company (Ann Arbor, MI, USA). (1S,2S)-2-[2-[[3-(1H-Benzimidazol-2-yl)propyl]methylamino]ethyl]-6-fluoro-1,2,3,4-tetrahydro-1-(1-methylethyl)-2-naphthalenyl cyclopropanecarboxylate dihydrochloride (NNC 55-0396; a highly selective T-type VGCC blocker), 8-bromo-cAMP (a cAMP analog), and 8-bromo-cGMP (a cGMP analog) were purchased from Tocris Bioscience (Bristol, UK). 1-Fluoro-2,4-dinitrobenzene (FDB; a creatine kinase inhibitor) was obtained from Sigma-Aldrich (St. Louis, MO, USA). Fluo-8 acetoxymethyl ester (Fluo-8 AM) was bought from AAT Bioquest (Sunnyvale, CA, USA). Mibefradil and Fluo-8 AM were each dissolved in DMSO to make a ×1,000 concentrated stock solution. NNC 55-0396, 8-bromo-cAMP, 8-bromo-cGMP, and FDB were each dissolved in distilled water to make a ×1,000 concentrated stock solution. The final concentration of DMSO was 0–0.2%. Our previous investigation confirmed that 0.1–0.3% DMSO does not significantly change the baseline ciliary beat frequency (CBF) [4 (link), 8 (link)].