 |
|
PERIODICAL
FASTING AND CALORIC RESTRICTION FOR LIFE EXTENSION,
DISEASE TREATMENT AND CREATIVITY.
(clinical and experimental data)
|
|
 |
| |
|
| 3.3
FASTING AND CALORIC RESTRICTION PRODUCE VARIOUS BIOLOGICAL
EFFECTS |
|
|
|
| |
| |
|
2005
School of Biosciences, The University
of Birmingham, Birmingham, United Kingdom.
We measured rate of oxygen
consumption (VO2) and body temperatures in 10 king
penguins in air and water. VO2 was measured during
rest and at submaximal and maximal exercise before
(fed) and after (fasted) an average fasting duration
of 14.4 +/- 2.3 days (mean +/- 1 SD, range 10-19 days)
in air and water. Concurrently, we measured subcutaneous
temperature and temperature of the upper (heart and
liver), middle (stomach) and lower (intestine) abdomen.
The mean body mass was 13.8 +/- 1.2 kg in fed and
11.0 +/- 0.6 kg in fasted birds. After fasting, resting
VO2 was 93% higher in water than in air (air: 86.9
+/- 8.8 ml (.) min(-1); water: 167.3 +/- 36.7 ml (.)
min(-1), P < 0.01), while there was no difference
in resting VO2 between air and water in fed animals
(air: 117.1 +/- 20.0 ml 02 (.) min(-1) water: 114.8
+/- 32.7 ml 02 (.) min(-1), P > 0.6). In air, VO2
decreased with body mass while it increased with body
mass in water. Body temperature did not change with
fasting in air whereas in water, there were complex
changes in the peripheral body temperatures. These
latter changes may, therefore, be indicative of a
loss in body insulation and of variations in peripheral
perfusion. Four animals were given a single meal after
fasting and the temperature changes were partly reversed
24 h after re-feeding in all body regions except the
subcutaneous, indicating a rapid reversal to a pre-fasting
state where body heat loss is minimal. The data emphasize
the importance in considering nutritional status when
studying king penguins and that the fasting-related
physiological changes diverge in air and water.
|
|
|
Institute of Normal Human Morphology,
Marche Polytechnic University, Via Tronto, 10/A, 60020
Ancona, Italy.
White adipose tissue (WAT)
is innervated by the sympathetic nervous system. A
role for WAT sympathetic noradrenergic nerves in lipid
mobilization has been suggested. To gain insight into
the involvement of nerve activity in the delipidation
process, WAT nerves were investigated in rat retroperitoneal
and epididymal depots after prolonged fasting. A significant
increase in tyrosine hydroxylase (TH) content was
found in epididymal and, especially, retroperitoneal
WAT by Western blotting. Accordingly, an increased
immunoreactivity for TH was detected by immunohistochemistry
in epididymal and, especially, retroperitoneal vascular
and parenchymal noradrenergic nerves. Neuropeptide
Y (NPY)-containing nerves were found around arteries
and in the parenchyma. Double-staining experiments
and confocal microscopy showed that most perivascular
and some parenchymal noradrenergic nerves also contained
NPY. Detection of protein gene product (PGP) 9.5,
a general marker of peripheral nerves, by Western
blotting and PGP 9.5-TH by double-staining experiments
showed significantly increased noradrenergic nerve
density in fasted retroperitoneal, but not epididymal
depots, suggesting that formation of new nerves takes
place in retroperitoneal WAT in fasting conditions.
On the whole, these data confirm the important role
of sympathetic noradrenergic nerves in WAT lipid mobilization
during fasting but also raise questions about the
physiological role of regional-dependent nerve adjustments
and their functional significance in relation to white
adipocyte secretory products.
|
|
|
Department of Biochemistry, University
of California, Riverside, CA 92521, USA.
It is widely held that caloric
restriction (CR) extends lifespan by preventing or
reducing the age-related accumulation of irreversible
molecular damage. In contrast, our results suggest
that CR can act rapidly to begin life and health span
extension, and that its rapid genomic effects are
closely linked to its health effects. We found that
CR begins to extend lifespan and reduce cancer as
a cause of death within 8 weeks in older mice, apparently
by reducing the rate of tumor growth. Further, 8 weeks
of CR progressively reproduces nearly three quarters
of the genomic effects of long-term CR (LTCR) in liver.
Fewer of the genomic effects of LTCR are rapidly reproduced
by the initiation of CR in the heart, but the changes
produced are keys to cardiovascular health. Thus,
the genomic effects of CR may be established more
rapidly in mitotic than in postmitotic tissues. Most
of the genomic effects of LTCR dissipate 8 weeks after
switching to a control diet. Consistent with these
results, others have shown that acute CR rapidly and
reversibly reduces the short-term risk of death in
Drosophila to that of LTCR treated flies. Further,
in late adulthood, acute CR partially or completely
reverses age-related alterations of liver, brain and
heart proteins. CR also rapidly and reversibly mitigates
biomarkers of aging in adult rhesus macaques and humans.
These data argue that highly conserved mechanisms
for the rapid and reversible enhancement of life-
and health-span exist for mitotic and postmitotic
tissues.
|
|
|
1998
Department of Veterinary Anatomy,
Faculty of Agriculture, Yamaguchi University, Japan.
The fine structural alterations
of hepatocytes of Japanese monkeys under 4 days of
fasting stress were analyzed morphometrically. One
of the conspicuous alterations was the enlargement
of mitochondria. The average diameter of mitochondria
in fasting group increased to approximately 1.89-fold
of that in control group, though their number did
not change. The number of peroxisomes was 1.36-fold
of that in control, though their area did not change.
In addition, many of r-ER were swollen and were vesiculated.
The appearance of bundle of actin-like stress fiber
also increased in the fasting animals. The glycogen
area as well as liver weight decreased in fasting
group.
|
|
|
|
|
| |
|
|
|
