title: Quantitative estimation of the total sulfide concentration in live tissues by two-photon microscopy.
abstract: Hydrogen sulfide (H2S) is a newly recognized transmitter, which protects various organs from oxidative stress. In this article, we report a ratiometric two-photon probe, TFCA, which can be excited by 750 nm femtosecond pulses, shows a 110-fold increase in the intensity ratio upon reaction with HS(-) and high selectivity for HS(-) and can visualize the total sulfide ([H2S] + [HS(-)]) distribution in live tissue by two-photon microscopy (TPM). We also developed a kinetic method to quantitatively estimate the total sulfide concentration ([H2S] + [HS(-)]) in live tissues. The kinetic method allowed us to measure the observed rate constants (kobs) for the sulfide-induced deazidation reaction of TFCA in live cells and tissues using TPM. The total sulfide concentration was calculated by using kobs = k2[HS(-)], with the k2 value determined in HEPES/EtOH (1/1, pH = 7.2), and [H2S]/[HS(-)] = [H(+)]/Ka. The total sulfide concentration was found to be nearly zero in HeLa cells and 4-7 μM in rat colon tissues.
authors.affiliation: Department of Chemistry, Korea University , 1-Anamdong, Seoul 136-701, Korea.
authors.forename: Chang Su
authors.initials: CS
authors.lastname: Lim
authors.forename: Sajal Kumar
authors.initials: SK
authors.lastname: Das
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Yang
authors.forename: Eun Sun
authors.initials: ES
authors.lastname: Kim
authors.forename: Hoon Jai
authors.initials: HJ
authors.lastname: Chun
authors.forename: Bong Rae
authors.initials: BR
authors.lastname: Cho
mesh_terms: D000818:Animals; D002470:Cell Survival; D002478:Cells, Cultured; D003106:Colon / Q000737:chemistry* / Q000166:cytology; D006367:HeLa Cells; D006801:Humans; D007700:Kinetics; D036641:Microscopy, Fluorescence, Multiphoton; D015394:Molecular Structure; D051381:Rats; D013440:Sulfides / Q000032:analysis*
chemical_list: D013440:Sulfides