INVESTIGADORES
RIGALLI Alfredo
congresos y reuniones científicas
Título:
Fluoride effects on oxygen consumption and oxidative stress
Autor/es:
FINA, BRENDA; DA ROS, EUGENIA; RIGALLI NICOLÁS FRANCISCO; RIGALLI ALFREDO
Lugar:
Szczecin
Reunión:
Congreso; XXXTH Conference of the International Society for Fluoride Research, advances in fluoride research; 2012
Institución organizadora:
International Society for Fluoride Research
Resumen:
<!--
@page { margin: 2cm }
H1 { margin-top: 0cm; margin-bottom: 0cm }
H1.western { font-family: "Times New Roman", serif; font-size: 12pt; so-language: es-ES }
H1.cjk { font-family: "DejaVu Sans"; font-size: 12pt }
H1.ctl { font-family: "DejaVu Sans"; font-size: 12pt; font-weight: normal }
P { margin-bottom: 0.21cm }
-->
Fluoride
effects
on oxygen consumption and oxidative stress.
Fina
BL, Da Ros ER, Rigalli N, Rigalli A
Bone
Biology Laboratory,
School of Medicine, Rosario National University, Rosario. Argentina.
Fluoride
(F) increases bone mass but the presence of inflammation has been
observed in F
treatments in rats. The lack of effectiveness of F as an
anti-osteoporotic drug could be due to inflammation. Inflammation
could be a
the consequence of an increase in reactive oxygen species (ROS), as a
result of modifications of the respiratory chain activity. The aim of
this work was to evaluate the effect of F on the oxygen uptake rate
(VO2)
in rats treated with sodium fluoride (NaF). Eighteen Sprague-Dawley
rats were divided into 3 groups (n=6 per group): NaF20,
NaF40,which
received orally 20 or 40 µmol NaF/100g bw/day for 30 days; and
Controls
thatreceived
water. VO2
(µmolO2/min.100g
bw) and fluoremia were measured in
vivo
before and after 90 min of NaF dose. After 30 days, euthanasia was
performed; plasma and mitochondrial glutathione peroxidase (GPx) and
catalase (CAT) activities and TBARS concentrations were measured as
indexes of oxidative stress. In
vitro,
the effect of F 100 µM on the VO2
of liver slices and of isolated mitochondria was also evaluated.
Finally, the addition of 100 µM of F on the activity of the
respiratory chain complexes was assessed. Results are expressed as
mean±SEM and differences were considered significant when p<0.05(*).
In
vivo,
VO2
decreasedafter
90 min of F dose in the NaF40 group (0min:171±22.6,
90min:147±22.6*). Plasma and mitochondrial TBARS levels and GPx and
CAT activities were higher in the NaF-treated groups. In
vitro,
F caused a decrease in the VO2
by liver slices (nmolO2/min.mg
prot) (0µM:47±4.5; 100µM:31±3.0*) and by mitochondria
(nmolO2/min.mg
prot) in state 4 (0µM:55±5.0; 100µM:29±3.5*) and state 3
(0µM:146±9.7; 100µM:87±9.3*) . The activity of complex I-III
(µmol.min-1.mg
prot-1)
was also inhibited by F (without F:1906±125; with F:1720±71*).
Conclusions:
F decreases VO2in
vivo
after an oral dose, and the same effect was observed in
vitro
after the addition of F at similar concentrations. The effect of F on
VO2
is observed only with high values of fluoremias. F also decreased VO2
by isolated mitochondria. The oxidative stress increased in the
treatment with NaF. This results support the hypothesis that the
presence of bone inflammatory foci in NaF-treated rats, could be the
consequence of an increase in ROS due to a modification of the
respiratory chain activity.