Health & Environmental Research Online (HERO)


NEtFOSAA (2991-50-6)


3 References Were Found:

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Inhibition of the adenine nucleotide translocator by N-acetyl perfluorooctane sulfonamides in vitro

Authors: O'Brien, TM; Oliveira, PJ; Wallace, KB (2008) Toxicology and Applied Pharmacology 227:184-195. HERO ID: 3859963

[Less] N-alkyl perfluorooctane sulfonamides have been widely used as surfactants on fabrics and papers, fire . . . [More] N-alkyl perfluorooctane sulfonamides have been widely used as surfactants on fabrics and papers, fire retardants, and anti-corrosion agents, among many other commercial applications. The global distribution and environmental persistence of these compounds has generated considerable interest regarding potential toxic effects. We have previously reported that perfluorooctanesulfonamidoacetate (FOSAA) and N-ethylperfluorooctanesulfonamidoacetate (N-EtFOSAA) induce the mitochondrial permeability transition (MPT) in vitro. In this study we tested the hypothesis that FOSAA and N-EtFOSAA interact with the adenine nucleotide translocator (ANT) resulting in a functional inhibition of the translocator and induction of the MPT. Respiration and membrane potential of freshly isolated liver mitochondria from Sprague-Dawley rats were measured using an oxygen electrode and a tetraphenylphosphonium-selective (TPP(+)) electrode, respectively. Mitochondrial swelling was measured spectrophotometrically. The ANT ligands bongkregkic acid (BKA) and carboxyatractyloside (cATR) inhibited uncoupling of mitochondrial respiration caused by 10 microM N-EtFOSAA, 40 microM FOSAA, and the positive control 8 microM oleic acid. ADP-stimulated respiration and depolarization of mitochondrial membrane potential were inhibited by cATR, FOSAA, N-EtFOSAA, and oleic acid, but not by FCCP. BKA inhibited calcium-dependent mitochondrial swelling induced by FOSAA, N-EtFOSAA, and oleic acid. Seventy-five micromolar ADP also inhibited swelling induced by the test compounds, but cATR induced swelling was not inhibited by ADP. Results of this investigation indicate that N-acetyl perfluorooctane sulfonamides interact directly with the ANT to inhibit ADP translocation and induce the MPT, one or both of which may account for the metabolic dysfunction observed in vivo.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Esterification prevents induction of the mitochondrial permeability transition by N-acetyl perfluorooctane sulfonamides

Authors: O'Brien, TM; Carlson, RM; Oliveira, PJ; Wallace, KB (2006) Chemical Research in Toxicology 19:1305-1312. HERO ID: 3859964

[Less] N-Alkyl perfluorooctane sulfonamides have been widely used as surfactants on fabrics and papers, fire . . . [More] N-Alkyl perfluorooctane sulfonamides have been widely used as surfactants on fabrics and papers, fire retardants, and anticorrosion agents, among many other commercial applications. The broad use, global distribution, and environmental persistence of these compounds has generated considerable interest regarding potentially toxic effects. We have previously reported that perfluorooctanesulfonamidoacetate (FOSAA) and N-ethylperfluorooctanesulfonamidoacetate (N-EtFOSAA) induce the mitochondrial permeability transition (MPT) in vitro, resulting in cytochrome c release, inhibition of respiration, and generation of reactive oxygen species. By synthesizing the corresponding methyl esters of FOSAA and N-EtFOSAA (methyl perlfuorinated sulfonamide acetates), we tested the hypothesis that the N-acetate moiety of FOSAA and N-EtFOSAA is the functional group responsible for induction of the MPT. Swelling of freshly isolated liver mitochondria from Sprague-Dawley rats was monitored spectrophotometrically and membrane potential (DeltaPsi) was measured using a tetraphenylphosphonium-selective (TPP(+)) electrode. In the presence of calcium, 40 microM FOSAA and 7 microM N-EtFOSAA each induced mitochondrial swelling and a biphasic depolarization of membrane potential. Mitochondrial swelling and the second-phase depolarization were inhibited by cyclosporin-A or the catalyst of K(+)/H(+) exchange nigericin, whereas the first-phase depolarization was not affected by either. In contrast, the methyl esters of FOSAA and N-EtFOSAA exhibited no depolarizing or MPT inducing activity. Results of this investigation demonstrate that the carboxylic acid moiety of the N-acetates is the active functional group, which triggers the MPT by perfluorinated sulfonamides.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Structural determinants of fluorochemical-induced mitochondrial dysfunction

Authors: Starkov, AA; Wallace, KB (2002) Toxicological Sciences 66:244-252. HERO ID: 1290853

[Less] Perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) are thought to induce peroxisome proliferation . . . [More] Perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) are thought to induce peroxisome proliferation and interfere with mitochondrial metabolic pathways. Direct measurements revealed that PFOA and the unsubstituted sulfonamide of perfluorooctane (FOSA) uncouple mitochondrial respiration by increasing proton conductance. The purpose of this investigation was to characterize structural determinants responsible for the mitochondrial uncoupling effect of several structurally related fluorochemicals. Included in the study were PFOA, PFOS, FOSA, the N-acetate of FOSA (perfluorooctanesulfonamidoacetate, FOSAA), N-ethylperfluorooctanesulfonamide (N-EtFOSA), and the N-ethyl alcohol [2-(N-ethylperfluorooctanesulfonamido)ethyl alcohol, N-EtFOSE] and N-acetic acid (N-ethylperfluorooctanesulfonamidoacetate, N-EtFOSAA) of N-EtFOSA. Each test compound was dissolved in ethanol and added directly to an incubation medium containing substrate-energized rat liver mitochondria. Mitochondrial respiration and membrane potential were measured concurrently using an oxygen electrode and a TPP+ -selective electrode, respectively. All of the compounds tested, at sufficiently high concentrations, had the capacity to interfere with mitochondrial respiration, albeit via different mechanisms and with varying potencies. At sufficiently high concentrations, the free acids PFOA and PFOS caused a slight increase in the intrinsic proton leak of the mitochondrial inner membrane, which resembled a surfactant-like change in membrane fluidity. Similar effects were observed with the sulfonamide N-EtFOSE. Another fully substituted sulfonamide, N-EtFOSAA, at high concentrations caused inhibition of respiration, the release of cytochrome c, and high-amplitude swelling of mitochondria. The swelling was prevented by cyclosporin A or by EGTA, indicating that this compound induced the mitochondrial permeability transition. The unsubstituted and mono-substituted amides FOSA, N-EtFOSA, and FOSAA all exerted a strong uncoupling effect on mitochondria resembling that of protonophoric uncouplers. Among these compounds, FOSA was a very potent uncoupler of oxidative phosphorylation, with an IC50 of approximately 1 microM. These data suggest that the protonated nitrogen atom with a favorable pKa is essential for the uncoupling action of perfluorooctane sulfonamides in mitochondria, which may be critical to the mechanism by which these compounds interfere with mitochondrial metabolism to induce peroxisome proliferation in vivo.