title: Supra-physiological doses of testosterone affect membrane oxidation of human neutrophils monitored by the fluorescent probe C₁₁-BODIPY⁵⁸¹/⁵⁹¹.
abstract: The purpose of this study was to determine the effects of supra-physiological doses of testosterone (TES) on membrane oxidation of activated human neutrophils in vitro using an innovative and sensitive technique: the real-time detection with the fluorescence probe C11-BODIPY(581/591). Methodological controls were performed with the lipid-soluble and powerful antioxidant astaxanthin at different neutrophil density cultures. Neutrophils from nine healthy young men (23.4 ± 2.5 years, 174.4 ± 7.0 cm height, and 78.3 ± 7.0 kg weight) were isolated and treated with 0.1 or 10 μM TES for 24 h and subsequently labeled with the free radical-sensitive probe C11-BODIPY(581/591) for monitoring membrane oxidation after neutrophil activation with phorbol-12-myristate-13-acetate (PMA). First-order exponential decay kinetic indicated that both 0.1 and 10 μM TES severely increased baseline membrane oxidation in non-activated human neutrophils (compared to control). However, similar kinetics of membrane oxidation were observed in control and 0.1 μM TES-treated neutrophils after PMA activation, whereas chemical activation did not alter the baseline higher rates of membrane oxidation in 10 μM TES-treated neutrophils. The data presented here support the hypothesis that TES exerts distinct effects on the membrane oxidation of human neutrophils, depending on its dose (here, 10(2) to 10(4)-fold higher than physiological levels in men) and on PMA activation of the oxidative burst. Furthermore, this paper also presents an innovative application of the free radical-sensitive probe C11-BODIPY(581/591) for monitoring (auto-induced) membrane oxidation as an important parameter of viability and, thus, responsiveness of immune cells in inflammatory processes.
authors.affiliation: Department of Physical Education, Paraná Federal University, Paraná, Curitiba, Brazil.
authors.forename: Tácito Pessoa
authors.initials: TP
authors.lastname: de Souza-Junior
authors.forename: André K
authors.initials: AK
authors.lastname: Yamada
authors.forename: Roberto
authors.initials: R
authors.lastname: Simão
authors.forename: Tatiana G
authors.initials: TG
authors.lastname: Polotow
authors.forename: Rui
authors.initials: R
authors.lastname: Curi
authors.forename: Zachary
authors.initials: Z
authors.lastname: Pope
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Willardson
authors.forename: Marcelo P
authors.initials: MP
authors.lastname: Barros
mesh_terms: D000328:Adult; D001896:Boron Compounds; D002250:Carbon Radioisotopes; D002462:Cell Membrane / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male; D018375:Neutrophil Activation; D009504:Neutrophils / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D018384:Oxidative Stress; D013739:Testosterone / Q000494:pharmacology*
chemical_list: C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D001896:Boron Compounds; D002250:Carbon Radioisotopes; D013739:Testosterone