BECAS
BASSO Agustin
artículos
Título:
Plasma esterases in the tegu lizard Tupinambis merianae (Reptilia, Teiidae):impact of biological variables and organophosphorus in vitro exposure.
Autor/es:
BASSO A., ATTADEMO A.M., LAJMANOVICH R.C., PELTZER P.M., JUNGES C., CABAGNA M.C., FIORENZA G.S. & SANCHEZ-HERNANDEZ J.C.
Revista:
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
Editorial:
SPRINGER HEIDELBERG
Referencias:
Lugar: Berlin; Año: 2012 vol. 19 p. 214 - 225
ISSN:
0944-1344
Resumen:
Purpose In this study, we determined normal serum
butyrylcholinesterase (BChE) and carboxylesterase (CbE)
activities in Tupinambis merianae in order to obtain reference
values for organophosphorus pesticide monitoring.
Methods Forty-two T. merianae individuals were grouped
by sex and size to identify potential differences in their
enzyme levels to allow for proper representation of normal
values for females, males, juveniles, and hatchlings. Mean
CbE was determined using two model substrates: alphanaphtylacetate
(α-NA) and p-nitrophenyl valerate (4-NPV).
BChE and CbE sensitivity to malaoxon (Mx) was also
evaluated as well as the possibility of BChE reactivation
with pyridine-2-aldoxime methochloride (2-PAM).
Results Mean adult females BChE was significantly higher
than adult males, juveniles, and hatchlings. No significant
differences were found between groups regarding CbE.
CbE (4-NPV) activity showed slightly negative correlation
with lizard snoutvent length, while BChE and CbE (α-NA)
showed no correlation with body size. Apparent IC50 values
for BChE and CbE (α-NA) suggested different sensitivities
among groups. CbE (4-NPV) could not be inhibited. All
Mx-inhibited groups treated with 2-PAM in a final concentration
of 2.8 mM showed clear signs of reactivation.
Conclusions In conclusion, the results demonstrate that (1)
plasma esterase activity did not vary with age and sex,
except for BChE activity, and (2) because biological and
environmental variables could be confounding factors in the
response of plasma cholinesterases, complementary biomarkers
like CbE inhibition and oxime-induced reactivation
of esterases are strongly recommended.