From: Doug Skrecky (oberon@vcn.bc.ca)
Date: Thu Mar 09 2000 - 18:15:14 MST
Citations: 1-4
<1>
Authors
Mockett RJ. Sohal RS. Orr WC.
Institution
Department of Biological Sciences, Southern Methodist University, Dallas,
Texas 75275, USA.
Title
Overexpression of glutathione reductase extends survival in transgenic
Drosophila melanogaster under hyperoxia but not normoxia.
Source
FASEB Journal. 13(13):1733-42, 1999 Oct.
Abstract
The purpose of this study was to test the hypothesis that overexpression of
glutathione reductase in transgenic Drosophila melanogaster
increases resistance to oxidative stress and retards the aging process.
Transgenic flies were generated by microinjection and subsequent mobilization
of a P element construct containing the genomic glutathione reductase gene of
Drosophila, with 4 kb upstream and 1.5 kb downstream of the
coding region. Transgenic animals stably overexpressed glutathione reductase
by up to 100% throughout adult life and under continuous exposure to 100%
oxygen or air. Under hyperoxic conditions, overexpressors had increased
longevity, decreased accrual of protein carbonyls, and
dramatically increased survival rates after recovery from a semi-lethal dose
of 100% oxygen. Under normoxic conditions, overexpression of glutathione
reductase had no effect on longevity, protein carbonyl
content, reduced glutathione, or glutathione disulfide content, although the
total consumption of oxygen was slightly decreased. Glutathione reductase
activity does not appear to be a rate-limiting factor in anti-aging defenses
under normoxic conditions, but it may become a limiting factor when the level
of oxidative stress is elevated.
<2>
Authors
Brack C. Bechter-Thuring E. Labuhn M.
Institution
Laboratory of Molecular Gerontology, University of Basel, Switzerland.
Title
N-acetylcysteine slows down ageing and increases the life span of
Drosophila melanogaster.
Source
Cellular & Molecular Life Sciences. 53(11-12):960-6, 1997 Dec.
Abstract
Ageing can be defined as the time-dependent decline of physiological
functions of an organism. The molecular causes for the ageing process are
multiple, involving both genetic and environmental factors. It has been
proposed that antioxidants may positively influence the ageing process,
protecting the organism against free radical-induced damage. Here we show
that the antioxidant N-acetylcysteine (NAC) has a life-extending effect on
Drosophila melanogaster. Dietary uptake of NAC results in a
dose-dependent increase in median and maximum life span. Flies fed on 1 mg/ml
NAC food live 16.6% longer; at 10 mg/ml, life span increases by 26.6%. We
have examined the effect of NAC treatment on protein and RNA levels: we
observe an NAC-dependent increase in absolute amounts of total RNA and
ribosomal RNA, but no differences in protein levels. The NAC effect on
longevity may involve differential expression of specific
mRNA genes, as suggested by RNA finger-printing experiments.
<3>
Authors
Anisimov VN. Mylnikov SV. Oparina TI. Khavinson VK.
Institution
Laboratory of Experimental Tumors, N.N. Petrov Research Institute of
Oncology, St. Petersburg, Russia.
Title
Effect of melatonin and pineal peptide preparation epithalamin on life span
and free radical oxidation in Drosophila melanogaster.
Source
Mechanisms of Ageing & Development. 97(2):81-91, 1997 Aug.
Abstract
It was shown previously that epithalamin delays age-related changes in
reproductive and immune systems and increases the life span of mice and rats.
These effects could be mediated by stimulating influences of epithalamin on
synthesis and secretion of melatonin and on free radical processes. A
comparative study on the effect of epithalamin and melatonin on both the life
span of Drosophila melanogaster (strain HEM) and on the
intensity of lipid peroxidation and activity of antioxidative enzymes in
their tissues was the main aim of this work. Melatonin and epithalamin was
added to the nutrition medium (100 micrograms/ml) during 2-3rd age of larvas.
For survival analysis the flies were passed (five coupes per vessel) each 3-7
days. Lipid peroxidation was evaluated as the level of ketodienes (KD) and
conjugated hydroperoxides (CHP) in fly tissues at the age of 11 days.
Activity of Cu, Zn-superoxide dismuatse (SOD) and catalase was evaluated as
well. The mean, median and maximum life span (MLS) were estimated. Mortality
rate (MR) was calculated as alpha in the Gompertz equation (R = Ro (exp alpha
t) and mortality rate doubling time (MRDT) as in 2/alpha. These parameters in
groups of male and female flies exposed to melatonin and in male flies
exposed to epithalamin were no different from the parameters for controls.
However, exposure to epithalamin was followed in females by a significant
increase in mean life span (by 17%, P < 0.02), of median (by 26%), of MLS by
14% and by a 2.12 times decrease of MR (P < 0.01) and MRDT (by 32%) compared
with female controls. The level of CHP and KD in the tissues of male control
flies was 40 and 49% less than that in females and indirectly correlates with
male life span. Exposure to melatonin was followed by a decrease in the level
of CHP and KD in females and the deletion of sex differences in them.
Exposure to epithalamin significantly decreased the level of CHP and KD in
female flies compared to controls (2.3 and 3.4 times, respectively, P <
0.001). Exposure to melatonin failed to influence the activity of catalase in
males but increased it in females by 24% (P < 0.02) and failed to influence
SOD activity both in males and females. Exposure to epithalamin was followed
by a significant increase in activity of catalse, 20% in males and 7% in
females and by an increase in SOD activity in males (41%). Thus, it was shown
that exposure to epithalamin significantly increases the mean life span and
MLS of female D.melanogaster and slowed down their aging rate by 2.12 times.
This effect is in good agreement with the inhibiting effect of epithalamin in
lipid peroxidation processes in fly tissues.
<4>
Authors
Le Bourg E. Minois N.
Institution
Laboratoire d'Ethologie et de Psychologie Animale, Universite Paul Sabatier,
Toulouse, France.
Title
Failure to confirm increased longevity in
Drosophila melanogaster submitted to a food restriction
procedure.
Source
Journals of Gerontology. Series A, Biological Sciences & Medical Sciences.
51(4):B280-3, 1996 Jul.
Abstract
Several studies have shown that, contrary to what occurs in rodents and in
some invertebrate species, food restriction has no positive effect on
longevity in Drosophila melanogaster.
However, Chippindale et al. (1993) reported that flies subjected to food
restriction, by modulating the yeast level, could live longer. In the present
study we used the same yeast levels as Chippindale et al. in an attempt to
confirm these results. No positive effect of food restriction on
longevity could be observed in either sex in mated and
virgin flies.
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