33 research outputs found
Alternative matrices for cortisol measurement in fish.
Plasma cortisol is the most commonly used indicator of stress in fish but, as the blood sampling procedure itself can be a source of stress, it would be helpful to measure cortisol using less invasive matrices. It is also necessary to find alternative matrices as stress indicators in dead fish in which blood sampling is impossible. In the present study, we investigated transport stress in three aquaculture species, European sea bass (Dicentrarchus labrax L.), common carp (Cyprinus carpio L.) and rainbow trout (Oncorhynchus mykiss Walbaum), by cortisol determination (radioimmunoassay) in plasma and other matrices (skin mucus, gut content, lateral muscle and caudal fin). Cortisol significantly increased after transport in all species and matrices, except in the sea bass gut content, where it remained unchanged. The three species responded to transport stress by producing different cortisol levels. In conclusion, the significant correlation found between plasma cortisol and most of the other matrices opens up the possibility of using them to evaluate stress in fish: mucus sampling is a less invasive method than blood sampling, and in addition to muscle and fin sampling, it can be used in postmortem fish
BIOMONITORAGGIO DELLA LAGUNA DI VENEZIA: INDICATORI BIOLOGICI IN Zosterisessor ophiocephalus e Tapes philippinarum
Lo scopo del presente studio \ue8 stato quello di valutare l\u2019espressione di alcuni bioindicatori comunemente utilizzati in programmi di biomonitoraggio in pesci e molluschi prelevati in due periodi dell\u2019anno e in diversi siti della Laguna di Venezia che, per la loro collocazione e per le caratteristiche idrologiche, possono essere pi\uf9 o meno soggette a possibili fonti inquinanti.
Le specie monitorate sono state il pesce bentonico Zosterisessor
ophiocephalus (Teleostei: Gobiidae) e la vongola verace Tapes philippinarum, animali particolarmente adatti al biomonitoraggio in quanto stanziali, vivono a stretto contatto con il fondo e sono reperibili in Laguna di Venezia.
Parallelamente alcuni individui di Z. ophiocephalus sono stati stabulati in vasche con acqua di mare per un periodo sufficiente detossificarsi, al fine di consentire una comparazione non solo tra i diversi siti di campionamento ma anche rispetto ad un controllo privo di contaminanti. I biomarcatori selezionati e analizzati sono stati: l\u2019espressione della vitellogenina (VTG), della citocromo P450 1A1 (CYP1A1) e dei principali marcatori
dello stress ossidativo, quali 4-idrossi nonenale (HNE), nitrotirosina (NT), malondialdeide (MDA) e acroleina, considerati ottimi indicatori di inquinamento ambientale. Inoltre sono stati valutati: l\u2019espressione del messaggero delle Heat Shock Protein 70 (HSP70) e, in entrambe le specie monitorate, i livelli di steroidi
sessuali (testosterone, estradiolo e progesterone) al fine di verificare eventuali variazioni imputabili alla presenza nell\u2019ambiente di distruttori endocrini cio\ue8 di sostanze inquinanti in grado di interferire con il sistema endocrino degli organismi.
Mediante analisi di immunoistochimica, Western blot, saggio T-BARS e Real Time PCR abbiamo potuto confermare quanto gi\ue0 riportato in letteratura: il bacino di Lido \ue8 la zona maggiormente impattata della Laguna poich\ue9 influenzata dalla presenza di un\u2019estesa area industriale e della citt\ue0 di Venezia. Un minor
impatto \ue8 stato invece riscontrato per le restanti aree monitorate. Tuttavia, al fine di di ottenere un quadro pi\uf9 completo dello stato dell\u2019intero ambiente lagunare, \ue8 necessario: identificare ulteriori ed efficaci bioindicatori, ampliare l\u2019area monitorata identificando altri siti di campionamento in tutti i bacini della Laguna di Venezia, aumentare il numero di esemplari da sottoporre a detossificazione utilizzando animali prelevati dai diversi bacini della Laguna di Venezia per allestire un esperimento di controllo completo
Biomonitoraggio della Laguna di Venezia: indicatori biologici in Zosterisessor ophiocephalus e Tapes philippinarum
Venice Lagoon is a transitional environment on the Adriatic coast influenced by such human activities as agriculture, industry, and tourism. For this reason, in the last year, numerous national and international projects have been carried out in order to evaluate the quality status of the lagoon environment demonstrating the presence of a wide range of contaminants in the environment.
The biomonitoring in the lagoon environment plays an important role in strategies and actions to identify, control and reduce the environmental problems. Biomonitoring programs usually involves the use of biomarkers, which represent biochemical, physiological or behavioural variation measured in tissues, biological fluids or the whole organism (Depledge and Fossi 1994).
In the present study, the expression of vitellogenin, cytochrome P450 1A1, HSP70 and oxidative stress biomarkers and sex steroids concentrations (progesterone, 17β-estradiol and testosterone) have been examined in different sites (Val di Brenta, Porto Canale, Ca’ Roman and Porto Marghera) of the Venice Lagoon monitoring their levels in the grass goby Zosterisessor ophiocephalus e in the clam Tapes philippinarum. Sampling sites were selected on the basis of data reported in literature (Nesto et al. 2007; Losso and Volpi Ghirardini, 2010).
Vitellogenin induction was detected in adult male of Z. ophiocephalus collected from the different sites evidencing high toxicological risk probably due to endocrine disrupting chemicals. Moreover, the highest levels of MDA and CYP1A1, measured spectrophotometrically by TBARS assay and by Real Time PCR respectively, were observed in animals sampled at the Porto Marghera site. The cellular localization of HNE and NT, investigated by an immunohistochemical approach, showed that immunopositivity was mainly localized in melanomacrophage-centres of spleen, kidney, liver and ovary. Both immunohistochemistry and Western blot analysis evidenced that HNE and NT were quantitatively higher in animals from Porto Marghera if compared with those sampled at the other sites.
In conclusion, as reported in literature (Losso and Volpi Ghirardini, 2010), most indicators have shown that the Lido basin, influenced by the presence of the industrial area and the city of Venice, is the most highly impacted area suggesting that oxidative stress markers, vitellogenin and cytochrome P4501A1 in aquatic organisms can be useful in biomonitoring of environmental pollution. However, HSP70 expression and sex steroid concentrations are not fast and suitable tools to investigate environmental quality.Lo scopo del presente studio è stato quello di valutare l’espressione di alcuni bioindicatori comunemente utilizzati in programmi di biomonitoraggio in pesci e molluschi prelevati in due periodi dell’anno e in diversi siti della Laguna di Venezia che, per la loro collocazione e per le caratteristiche idrologiche, possono essere più o meno soggette a possibili fonti inquinanti.
Le specie monitorate sono state il pesce bentonico Zosterisessor ophiocephalus (Teleostei: Gobiidae) e la vongola verace Tapes philippinarum, animali particolarmente adatti al biomonitoraggio in quanto stanziali, vivono a stretto contatto con il fondo e sono reperibili in Laguna di Venezia. Parallelamente alcuni individui di Z. ophiocephalus sono stati stabulati in vasche con acqua di mare per un periodo sufficiente a detossificarsi, al fine di consentire una comparazione non solo tra i diversi siti di campionamento ma anche rispetto ad un controllo privo di contaminanti.
I biomarcatori selezionati e analizzati sono stati: l’espressione della vitellogenina (VTG), della citocromo P450 1A1 (CYP1A1) e dei principali marcatori dello stress ossidativo, quali 4-idrossi nonenale (HNE), nitrotirosina (NT), malondialdeide (MDA) e acroleina, considerati ottimi indicatori di inquinamento ambientale. Inoltre sono stati valutati: l’espressione del messaggero delle Heat Shock Protein 70 (HSP70) e, in entrambe le specie monitorate, i livelli di steroidi sessuali (testosterone, estradiolo e progesterone) al fine di verificare eventuali variazioni imputabili alla presenza nell’ambiente di distruttori endocrini cioè di sostanze inquinanti in grado di interferire con il sistema endocrino degli organismi.
Mediante analisi di immunoistochimica, Western blot, saggio T-BARS e Real Time PCR abbiamo potuto confermare quanto già riportato in letteratura: il bacino di Lido è la zona maggiormente impattata della Laguna poiché influenzata dalla presenza di un’estesa area industriale e della città di Venezia. Un minor impatto è stato invece riscontrato per le restanti aree monitorate. Tuttavia, al fine di di ottenere un quadro più completo dello stato dell’intero ambiente lagunare, è necessario: identificare ulteriori ed efficaci bioindicatori, ampliare l’area monitorata identificando altri siti di campionamento in tutti i bacini della Laguna di Venezia, aumentare il numero di esemplari da sottoporre a detossificazione utilizzando animali prelevati dai diversi bacini della Laguna di Venezia per allestire un esperimento di controllo completo
Sex steroids in tapes philippinarum (Adams and Reeve 1850) during the gametogenic cycle: preliminary results.
It is well known that a wide variety of endocrinedisrupting
chemicals (EDCs) (e.g. organotin compounds,
heavy metals, herbicides, xenoestrogen compounds) can induce
endocrine alterations in aquatic invertebrates, often
causing reproductive disorders. Although these phenomena
are of great concern, mostly in coastal and estuarine environments,
few data are available about the mechanism of
action of EDCs, mainly due to lack of knowledge about the
invertebrate endocrine system.
To understand the possible mechanism of action of
EDCs better, the presence and patterns of variation of sexual
steroids, progesterone, testosterone and 17\u3b2-estradiol
were measured in the whole body of the clam Tapes philippinarum
by specific and opportunely validated microtitre
radioimmunoassays (RIAs). Female steroid concentrations
showed similar trends, with higher values during spawning
and lower ones in post-spawning and gametogenesis periods.
Conversely, in males, sexual steroids varied over the
year: progesterone remained unchanged, with values similar
to those of females in gametogenesis, whereas testosterone
and 17\u3b2-estradiol showed a significant decrease
during gametogenesis only. Seasonal variations in clam
steroid levels may reflect their role in modulating reproduction.
All hormones were unexpectedly high in the resting/
early developing stage, during which gonadal tissue is
scarce, indicating that digestive gland may have a biosynthetic
steroid capacity or accumulation. Although these
results are preliminary, evaluation of sexual steroids in
T. philippinarum during the gametogenic cycle represent
the first step for future research aimed at understanding
the physiological role of these hormones and their potential
interaction with EDCs
Behaviour and welfare of growing rabbits housed in cages and pens
The present study compared behaviour, fear and stress levels of 456 crossbred rabbits reared in bicellular wire-net cages (2 rabbits/cage) with top and wire floor or open-top collective pens (20 to 54 rabbits/pen) with wooden slatted floor. The effect of pen size (small vs. large) and stocking density (12 vs. 16 rabbits/m2) in collective pens was also evaluated. The rabbits kept in collective pens rested more than those in bicellular cages (82.1% vs. 77.6% of observed time; P<0.01), spent less time feeding (7.8% vs. 10.9%), allo-grooming (0.65% vs. 1.58%) and more time moving (0.81% vs. 0.35%) (P<0.01). The percentage of rabbits sensitive in the tonic immobility test was lower in rabbits kept collectively compared to those in bicellular cages (76.6% vs. 93.8%; P=0.03). In the open field test, the rabbits kept in collective pens moved less (40.4 s vs. 57.2 s; P<0.001) and explored the arena for a shorter time (345 s vs. 371 s; P<0.001) than rabbits housed in bicellular cages; instead, these rabbits stood still for a longer period of time (82.1 s vs. 38.7 s; P<0.001). The rabbits kept in collective pens displayed a higher hair corticosterone level (15.7 ng/g vs. 6.7 ng/g for rabbits from the cages; P<0.001). Within collective housing systems, stocking density had no effect whereas increasing pen size numerically reduced the time rabbits spent eating (8.30% vs. 6.55%), self-grooming (6.39% vs. 5.47%) and time spent resting (81.1% vs. 84.1%). In conclusion, rabbits housed in collective pens displayed a more complete behavioural pattern, despite resting more; they were more bold toward humans, but more fearful in a new environment than rabbits from cages. In the tested conditions, pen size and stocking density within collective systems exerted only a weak effect on behaviour, fear and stress levels of meat rabbits
Alternative matrices for cortisol measurement in fish.
Plasma cortisol is the most commonly used indicator
of stress in fish but, as the blood sampling procedure
itself can be a source of stress, it would be helpful to
measure cortisol using less invasive matrices. It is
also necessary to find alternative matrices as stress
indicators in dead fish inwhich blood sampling is impossible.
In the present study, we investigated transport
stress in three aquaculture species, European
sea bass (Dicentrarchus labrax L.), common carp (Cyprinus
carpio L.) and rainbow trout (Oncorhynchus
mykiss Walbaum), by cortisol determination (radioimmunoassay) in plasma and other matrices (skin
mucus, gut content, lateral muscle and caudal fin).
Cortisol signi\ua2cantly increased after transport in all
species and matrices, except in the sea bass gut content,
where it remained unchanged. The three species
responded to transport stress by producing
di\ua1erent cortisol levels. In conclusion, the significant
correlation found between plasma cortisol and most
of the other matrices opens up the possibility of using
them to evaluate stress in fish: mucus sampling is a
less invasive method than blood sampling, and in addition
to muscle and fin sampling, it can be used in postmortem fish
Whole-body concentrations of cortisol and sex steroids in white sturgeon (Acipenser transmontanus, Richardson 1836) during early development and stress response
In general little is known about hormones and the ontogeny of the stress response in the early developmental stages of chondrostean fishes and in particular of white sturgeon (Acipenser transmontanus, Richardson 1836). In this study, we measured for the first time cortisol and sex steroids (testosterone and estradiol) in eggs, larvae, post-larvae,
and fry of white sturgeon by radioimmunoassay (RIA), to elucidate some endocrine aspects of its development. The cortisol, testosterone, and 17b-estradiol of maternal origin found in unfertilized eggs of white sturgeon probably regulate both growth and development of the
embryo. Cortisol decreased after fertilization, whereas testosterone and 17b-estradiol did not significantly change. During the late stages of embryo development and immediately after hatching, endogenous production of cortisol and sexual steroids, respectively, occurred. Sex steroids may be physiological inducers of gonad sex differentiation in sturgeon. All steroids showed an increase 10 days post-hatch (dph), near the transition
from an endogenous to an exogenous energy source. Cortisol maintained the same basal levels even after metamorphosis, whereas testosterone and 17b-estradiol declined significantly in post-larvae at 35 and 45 days post-hatch. In addition, to evaluate the ontogeny of
a functional hypothalamic-pituitary-interrenal (HPI) axis, larvae and fry were submitted to acute stress. The HPI axis did not seem to be functional on the first day post-hatch, but
became so from the third day post-hatch onward