squeegee
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http://www.google.com/url?sa=t&rct=...64DwBg&usg=AFQjCNGKyDFeQHd_Y_pTHDNkq5bSV8MVDQ
SENSITIVITY TO OXIDATIVE STRESS: SEX MATTERS
Tatjana Marotti, Sandra Sobočanec, Željka Mačak-Šafranko, Ana Šarić,
Borka Kušić, Tihomir Balog
Division of molecular medicine, Institute «Ruđer Bošković», Zagreb, Croatia
Summary
The excessive production of free radicals in organism and the imbalance between
the concentration of these and the antioxidant defences has been related to the process
of aging. It has been postulated that oxidative processes and antioxidant defence can bee
sex related. Besides, we have noticed that at old age 60% of male mice developed hepatocellular
tumors which were absent in females. Thus, it is of interest to determine oxidative
and antioxidative status of aging male and female mice under conventional oxygen
conditions and in 100-percet oxygen with possible mechanisms involved. The process
of lipid peroxidation and antioxidant enzyme activity was age and sex-related, favouring
males over females throughout the lifespan. The sensitivity of a cell to free radical attack
apparently depends on the relationship among antioxidant enzymes rather than on
absolute activities of individual antioxidant enzymes. Indeed, our results imply stronger
correlative links in old female than male mice, which might explain why old females are
better protected from oxidative stress than males. In the liver of hyperoxia treated mice
sex-related difference was found at the physiological level observing malondialdehyde
(MDA) increment (one of the end products of lipid peroxidation) and increased catalase
(CAT) activity only in male mice. Hyperoxia did upregulate a stress responsive enzyme
heme-oxygenase-1 (HO-1), but only in female mice. Also, stress related izoenzymes of
the cytochrome P450 family were changed. In female mice Cyp1A1 and Cyp1A2 were
downregulated and Cyp2A5 was upregulated. The results of our study suggest that females
are less susceptible to oxidative stress by two major mechanisms: upregulated
expression of HO-1 genes and different expression of certain P450 enzymes.
SENSITIVITY TO OXIDATIVE STRESS: SEX MATTERS
Tatjana Marotti, Sandra Sobočanec, Željka Mačak-Šafranko, Ana Šarić,
Borka Kušić, Tihomir Balog
Division of molecular medicine, Institute «Ruđer Bošković», Zagreb, Croatia
Summary
The excessive production of free radicals in organism and the imbalance between
the concentration of these and the antioxidant defences has been related to the process
of aging. It has been postulated that oxidative processes and antioxidant defence can bee
sex related. Besides, we have noticed that at old age 60% of male mice developed hepatocellular
tumors which were absent in females. Thus, it is of interest to determine oxidative
and antioxidative status of aging male and female mice under conventional oxygen
conditions and in 100-percet oxygen with possible mechanisms involved. The process
of lipid peroxidation and antioxidant enzyme activity was age and sex-related, favouring
males over females throughout the lifespan. The sensitivity of a cell to free radical attack
apparently depends on the relationship among antioxidant enzymes rather than on
absolute activities of individual antioxidant enzymes. Indeed, our results imply stronger
correlative links in old female than male mice, which might explain why old females are
better protected from oxidative stress than males. In the liver of hyperoxia treated mice
sex-related difference was found at the physiological level observing malondialdehyde
(MDA) increment (one of the end products of lipid peroxidation) and increased catalase
(CAT) activity only in male mice. Hyperoxia did upregulate a stress responsive enzyme
heme-oxygenase-1 (HO-1), but only in female mice. Also, stress related izoenzymes of
the cytochrome P450 family were changed. In female mice Cyp1A1 and Cyp1A2 were
downregulated and Cyp2A5 was upregulated. The results of our study suggest that females
are less susceptible to oxidative stress by two major mechanisms: upregulated
expression of HO-1 genes and different expression of certain P450 enzymes.