Autor(es):
Candeias, M 
; Alves-Pereira, I ; Ferreira, R
Data: 2010
Identificador Persistente: http://hdl.handle.net/10174/6341
Origem: Repositório Científico da Universidade de Évora
Assunto(s): IPU; alcohol dehydrogenase
Descrição
The isoproturon, a herbicide which acts as a photosynthesis
inhibitor is consider by some authors as toxic to humans having
ability for tumors induction. When this phenylurea is metabolized
by biotransformation systems can generate oxidative stress,
activating electron transport chains present at mitochondria and
endoplasmic reticulum and causing an increase of intracellular ROS.
Having in account exposure above, the main purpose of this work was to compare the effects of isoproturon on cell growth, glutathione
level and catalase T (CAT), glutathione peroxidase (GPx),
alcohol dehydrogenase (ADH) and lactate dehydrogenase (LDH)
activities of Saccharomyces cerevisiae UEME3,
wildtype
strain of
Alentejo, Portugal, growing in YEPD, YED and YEP media. Cells at
midexponential
phase were inoculated in each medium and incubated
during 72 h in a water bath with orbital stirring, at 28 ◦C,
in the absence or presence of 100mM isoproturon. Samples from
each treatment were used to obtain growth curves and to prepare
post12,000×g
supernatant, used for determination of GSH level
as well as CAT T, GPx, ADH and LDH activities. The results show that
isoproturon cause a significant increase of cell survival, GSH/GSSG
ratio, LDH activities in yeast growing in presence of peptone plus
glucose or peptone. Despite, isoproturon cause a decrease of CAT
T and GPx ability to scavenger H2O2 or lipid hyroperoxides, it was
also observed an increase of ADH activity in all media tested. The
maintenance of high levels of GSH, as well as, the dehydrogenases
responses can be interpreted as a stress adaptive mechanism to
isoproturon where ADH and LDH are crucial enzymes for cytosolic
NAD+ recycling.
