2.
EFFECT OF DIET ON HAIR CORTISOL AND DHEA CONCENTRATIONS IN MOUSEAntonella Comin,
Marta Montillo,
Tanja Peric,
Silvia Gazzin,
Mirco Corazzin,
Alberto Prandi, objavljeni povzetek znanstvenega prispevka na konferenci
Opis: Obesity and MetS (Metabolic Syndrome) are both linked to persistent long-term hormonal
and metabolic changes. In most of the studies, cortisol (C) and dehydroepiandrosterone
(DHEA) concentrations have been measured in obese and normal-weight subjects,
obtaining heterogeneous results. Plasma, saliva and urine, matrices that represent timepoint
or short-term steroids exposure, were used for these studies. The aim was to study
C, DHEA and C/DHEA ratio of mice pups in the hair, matrix capable of providing
cumulative hormonal exposure. Sixty C57Bl/6 mice pups (30 males and 30 females)
were housed in a temperature-controlled environment (22±2°C) and on a 12h light/dark
schedule, under ad-libitum access to food and water for 16 weeks (welfare: Italian Law
Decree 116-92 and EC Directive 86-609-EEC). Control and experimental diets were
offered immediately after weaning (3 weeks old pups), for 16 weeks. Four experimental
checkpoints were established (T1: 4 weeks, T2: 8 weeks, T3: 12 weeks and T4: 16 weeks
of diet). T3 and T4 showed the hormonal concentrations of pubertal animals. Twentyseven
pups (13 females and 14 males) were randomly group-housed in cages (6 for T1, 5
for T2, 6 for T3, 10 for T4) and assigned to control diet (CTRL: D12328, Research Diets,
New Brunswick, NJ). 33 pups (17 females and 16 males) were randomly group-housed in
cages (5 for T1, 6 for T2 and T3, 16 for T4) and assigned to the HFHC diet (HFHC: D12331, Research Diets, New Brunswick, NJ - plus 42g/L fructose/sucrose in drinking
water). At each experimental checkpoint, all the animals of one cage for each
experimental group were suppressed. Hair strands were carefully cut with scissors as
close as possible to the skin from the back of the mice, paying attention to not to wound
the animals. Hair was stored in an envelope at RT in a dry room until use. C and DHEA
hair concentrations was measured by a solid-phase microtiter RIA assay (Peric et al., 2016 adapted in the mouse). Only at 8 weeks the HFHC group showed significantly
higher C concentrations than the CTRL group (1.56±0.06 vs 1.92±0.130 pg/mg; P<0.05).
DHEA concentrations were significantly reduced in the HFHC group than the CTRL
group at 4 (114.64±13.93 vs 69.08±5.33 pg/mg; P<0.05), 8 (71.67±7.08 vs 50.38±4.74
pg/mg; P<0.05), 12 (73.27±8.29 vs 41.59±1.60 pg/mg; P<0.01) and 16 weeks
(65.26±3.35 vs 55.05±1.84 pg/mg; P<0.05). The C/DHEA ratio was significantly
increased in the HFHC than the CTRL group, at 8 (0.023±0.002 vs 0.040±0.005; P<0.01),
12 (0.024±0.003 vs 0.036±0.004; P<0.05) and 16 weeks (0.019±0.001 vs 0.025±0.002;
P<0.01). The gender effect was not significant. Taking into account the lag time required
for the hair emersion from the skin (about 1 week), the significant stimulation of the C at
8 weeks in the HFHC group refers to its chronic elevation from 5 to 7 weeks of treatment
when the animals were not pubertal. Conversely, DHEA shows a chronic reduction in
obese mice leading to consider an independent adrenal regulation of C and DHEA, both
stimulated by ACTH.
Research was supported by the Project CBM (MIUR DM60643).
Peric et al. 2016 J Appl Anim Welf Sci 18:1-8.
Ključne besede: DIET, HAIR, CORTISOL, DHEA, MOUSE
Objavljeno v RUNG: 21.07.2016; Ogledov: 5728; Prenosov: 0
Gradivo ima več datotek! Več...