PERSONAL DE APOYO
LONNE Maria Noelia
congresos y reuniones científicas
Título:
Responses of zebrafish (Danio rerio) hepatocytes co-exposed to benzo[a]pyrene and to the carbon nanomaterial fullerene (C60)
Autor/es:
LONNÉ, M.N.; RIBAS FERREIRA, J.L.; SOARES CHAVES, I.; DE LA TORRE, F.R; MONSERRAT, J.M
Lugar:
Bombinhas, Santa Catarina, Brasil
Reunión:
Congreso; XI Congresso Brasileiro de Ecotoxicologia; 2010
Resumen:
<!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;
mso-font-charset:0;
mso-generic-font-family:roman;
mso-font-pitch:variable;
mso-font-signature:-1610611985 1107304683 0 0 159 0;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;
mso-font-charset:0;
mso-generic-font-family:swiss;
mso-font-pitch:variable;
mso-font-signature:-1610611985 1073750139 0 0 159 0;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{mso-style-unhide:no;
mso-style-qformat:yes;
mso-style-parent:"";
margin-top:0cm;
margin-right:0cm;
margin-bottom:10.0pt;
margin-left:0cm;
line-height:115%;
mso-pagination:widow-orphan;
font-size:11.0pt;
font-family:"Calibri","sans-serif";
mso-fareast-font-family:Calibri;
mso-bidi-font-family:"Times New Roman";
mso-ansi-language:PT-BR;
mso-fareast-language:EN-US;}
.MsoChpDefault
{mso-style-type:export-only;
mso-default-props:yes;
font-size:10.0pt;
mso-ansi-font-size:10.0pt;
mso-bidi-font-size:10.0pt;
mso-ascii-font-family:Calibri;
mso-fareast-font-family:Calibri;
mso-hansi-font-family:Calibri;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:70.85pt 3.0cm 70.85pt 3.0cm;
mso-header-margin:36.0pt;
mso-footer-margin:36.0pt;
mso-paper-source:0;}
div.WordSection1
{page:WordSection1;}
-->
In this study the toxic responses in zebrafish
hepatocytes co-exposed to the polycyclic aromatic hydrocarbon benzo[a]pyrene
(BaP) and the carbon nanomaterial fullerene (C60) were analyzed. Fullerene suspensions were obtained after shaking in Milli Q water for
two months under constant shaking and under constant fluorescent light at
ambient temperature. Particles size was characterized by transmission electron
microscopy, being confirmed its nanometric scale. Hepatocytes were kept at 28 °C, in RPMI culture medium
with 10% BSA. Mitochondrial functionality (MF), registered by MTT reduction,
was used as a cell viability estimate. Concentrations of 0.01, 0.1 and 1.0 mg
BaP/L did not alter the viability when compared to control group and the opposite was observed
for the concentrations of 10.0 and 100.0 mg BaP/L (p<0.05). Then, the effect
of co-exposure to BaP (0.01-1.0 mg BaP/L) with 1 mg C60/L -a
concentration that did not alter cell viability- was evaluated. After 4 h of
incubation, several parameters were evaluated:
MF and intracellular concentration of reactive oxygen species (ROS); glutathione-S-transferase
(GST) activity and intracellular accumulation of BaP and its metabolites.
Regarding ROS, results showed that co-exposure of hepatocytes to 1.0 mg BaP/L
and 1 mg C60/L caused a significant decrease in their concentration
in relation to cells only exposed to 1.0 mg/L BaP. GST activity increased in a
dose-dependent manner (p<0.05) without C60 for 0.1 and 1 mg/mL
BaP concentrations and in presence of C60, a significant reduction
was observed for all concentrations tested. In addition, the intracellular
accumulation of BaP and its metabolites was significantly higher and similar both
in presence and absence of C60 for the 1 mg/L of BaP concentration,
showing that C60 did not facilitated BaP entry into the cells.
Taking into account that mitochondria are the main source of ROS production,
the decrease in their concentration and the lower MF in hepatocytes exposed to
BaP and C60 suggest that mitochondrial functionality was altered.
The GST activity was higher for increasing values of BaP concentration, as
expected, but the presence of C60 caused a significant loss in the
detoxifying capacity of the cells. However the possibility of C60
being adsorbing BaP and thus reducing GST induction must be yet to be analyzed.
