1,720,982 research outputs found
Morphological and biochemical responses to environmental contaminants in farmed and wild European sea bass (Dicentrarchus labrax).
No full textThe presence of environmental pollutants in both wild and cultured fish is cause of concern. The European sea bass (Dicentrarchus labrax L., Teleostei, Moronidae) represents one of the most diffused marine species cultured in the Mediterranean areas. Aim of this study was to investigate the relationships of polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDDs and PCDFs), dioxin-like and non dioxin-like polychlorinated biphenyl (DL and NDL-PCBs) levels in the muscle of wild and cultured sea bass with morphological and enzymatic activities as biochemical biomarkers of exposure. In farmed fish, levels of contaminants were lower than those detected in other studies. The low level of contamination was confirmed both by enzymatic activities and by gonad, liver and gill morphology showing absence of chronic alterations.
Keywords: environmental pollutants, biomarker, seabass, aquaculture
Exposure to Lambro river water disrupts spermatogenesis in Xenopus laevis
No full textAfrican clawed toad (Xenopus laevis) has been established as a very suitable model for studying the effects of Endocrine Disrupting Chemicals (EDCs) on reproductive biology. In a previous study we demonstrated severe alterations of testis organization (i.e. reduction of tubule diameter and number of germ cell nests and occurrence of small oocytes) in adult male X. laevis following a four weeks exposure to water from the river Lambro (LAM), a contaminated watercourse from Northern Italy. Data were compared with controls and exposed to ethinylestradiol (EE2), tamoxifen (TAM), methyl-dihydrotestosterone (MDHT) and flutamide (FLU), 10-8 M, as positive controls for (anti)estrogenic and (anti)androgenic activities. In this study, following the same experimental design, our attention was focused on the effects on the spermatogenic process. Germ cell nest profile was analysed in both paraffin and resin embedded testis within ten tubule sections for each specimen, numbered and classified into one of four different categories based on the following germ cell type: spermatogonia B (SPGB), primary spermatocytes (SPCI), secondary spermatocytes (SPCII), spermatids (SPD). The contingency test showed a general decrease of cell nests in LAM, EE2 and FLU exposed males and a general increase of cell nests in MDHT and TAM exposed males. Moreover, LAM exposed males, as well as EE2 and FLU exposed males, showed an increase in the number of SPGB nests and a decrease of SPD nests. A decrease of SPCII and an increase of SPCI nests was observed in 100% and in 44.4% EE2 exposed specimen sections, respectively. A decrease of SPCII and an increase of SPCI nests was observed in about 50% and 90% FLU exposed specimen sections, respectively. Even this last feature was less evident in LAM exposed males, data seem to confirm that Lambro river water is polluted by the concomitant presence of EDCs with mainly estrogenic and anti-androgenic modes of actions
In vivo exposures of carp to graded concentration of Bisphenol
No full textA wide range of environmental pollutants called Endocrine Disrupters (ED) can mimic steroid hormones causing adverse health effects. Previous studies have demonstrated that bisphenol-A (BPA) represents a relevant compound within chemicals present in water and sediments coming from a polluted area of the Po plain. This study is aimed to investigate the role of BPA in inducing ED effects at both morphological and biochemical level. One year old immature carps (n=120) were exposed for 14 days (OECD guideline 204) to BPA graded concentrations (1μg/L–10μg/L–100μg/L-1000μg/L) starting from the environmental value. Morphological alterations of gonads were described and compared to Vitellogenin (VTG) and sex steroid levels. Severe alteration of testis structure were observed in males starting from 10μg/L. Several males lost the typical lobule structure showing spermatogenic cysts intermingled with free SPZ often degenerating into the lumen. Females exposed to the highest concentration (1000μg/L) showed alteration in gonad. Carps exposed to the highest concentration showed intersexuality (10%). In males exposed to the highest concentration (1000μg/L) a significant increase of estradiol-17 (E2) plasma level and a steroid ratio E2/11KT (11-ketotestosterone) upper than 1, indicative of active females in carp, were observed. Vitellogenin plasma levels significantly increased in males, starting from 1000 μg/L, and females, starting from 100 μg/L
Cloning of mRNA CYP19A1 in the carp (Cyprinus carpio)
No full textExposure to Endocrine-Disrupting Chemicals (EDCs) is suspected to be the cause for the increasing number of reproductive disorders in wildlife. It is well established that many chemicals in the environment can interfere with signalling mechanisms/hormonal regulation of fish at concentrations considerably below those causing cellular toxicity. Key targets for EDCs include steroid hormone receptors and steroidogenic enzyme systems. Cytochrome P450arom (CYP19A1 gene), a key enzyme in the hormonal steroidogenic pathway, mediates the conversion of androgens to estrogens. This work aimed to study the effects of EDCs on the expression of CYP19A1 mRNA in the common carp (Cyprinus carpio). For this purpose, we have cloned a full-length cDNA encoding cytochrome P450 aromatase. In particular we have used degenerated primers designed on the conserved regions of CYP19A1 of other teleost species. On the basis of such sequence we have designed PCR primers for the semi-quantitative PCR assays. RT-PCR revealed that the CYP19A1 was highly expressed in the ovary and, at very low levels, in the testis. Effects of a 14 day exposure (OECD guideline 204) to graded concentrations of bisphenol A (BPA) on the expression of mRNA CYP19A1 are discusse
Altered hepatic parameters in Sparus aurata juveniles exposed to Nonylphenol and 4tert-Octylphenol contaminated feed.
No full textBiomarcatori di stress in spigole allevate
No full textLe risposte che l’organismo realizza quando e sottoposto ad uno stress metabolico od ambientale rappresentano potenziali biomarcatori utilizzabili per il monitoraggio. Mediante lo studio delle risposte immediate un biomarcatore permette infatti di prevedere con notevole anticipo l’insorgenza di effetti nocivi come cancerogenesi, alterazioni patologiche, diminuzione delle capacita riproduttive, e mortalita. La reazione dell’organismo prevede la sintesi di particolari proteine dello stress quali le metallotioneine (MT) e le heat shock protein (Hsp). In particolare, livelli alterati di MT nei diversi tessuti possono rappresentare un indice specifico, anche se indiretto, di inquinamento ambientale da metalli pesanti, mentre le Hsp, ed in particolare l’HSP70 e 90, che possono essere indotte da un ampio spettro di fattori di stress, sono considerate buoni indicatori del benessere dei pesci in condizioni di allevamento. Questo studio e stato condotto su esemplari di spigola (Dicentrarchus labrax) campionati nel mese di febbraio 2009 a fine ingrasso, presso due diversi tipi di impianto 1) off-shore e 2) in-shore. Campioni di tessuto muscolare sono stati immediatamente congelati per le successiva determinazione del contenuto di metalli pesanti (Hg, Pb, Cd e Cr). I tenori di piombo (Pb), mercurio (Hg), cadmio (Cd) e cromo (Cr) sono stati determinati per via umida previa mineralizzazione del tessuto e successiva lettura in assorbimento atomico. Il fegato e stato prelevato in toto, pesato e immediatamente una piccola porzione (n=10 per ogni allevamento) e stata immersa in RNA later e congelata a -20°C per l’analisi semi-quantitativa dell’espressione di MT e HSP 70 e 90 mediante RT-PCR. I valori di Hg, Pb e Cd espressi in mg/Kg pesce umido sono risultati sempre al di sotto dei limiti previsti dalle normative relative ai contaminanti nei prodotti alimentari (REGOLAMENTO (CE) N. 1881/2006 DELLA COMMISSIONE del 19 dicembre 2006 che definisce i tenori massimi di alcuni contaminanti nei prodotti alimentari. In particolare il Cd e sempre risultato ai limiti della soglia di rilevabilita del metodo. Il dato analitico e supportato dai dati ottenuti con i biomarcatori utilizzati in questo studio. Infatti, l’espressione delle MT e risultata su livelli di base, senza nessuna differenza significativa nei due siti. Inoltre non sono state rilevate differenze significative nell’espressione di HSP70 e HSP90 confermando, con questi parametri, l’adozione di condizioni di allevamento complessivamente atte a ridurre al minimo lo stress. Parte dei risultati sono stati ottenuti nell’ambito del progetto IZS LT 2006 finanziato dal Ministero della Salut
Partial cloning of P450arom mRNA in the carp (Cyprinus carpio).
No full textExposure to Endocrine-Disrupting Chemicals” (EDCs) is suspected to be the cause for the increasing number of reproductive disorders in wildlife. A wide range of environmental pollutants can mimic steroid hormones causing adverse health effects in intact organisms or their progeny, secondary to changes in endocrine functions The synthesis of estrogens is dependent on the activity of the steroidogenic enzyme P450 aromatase (P450arom) that catalyses the conversion of C-19 androgens into C-18 estrogens in the ovary, testis, placenta, skin fibroblasts, adipose and nervous tissue. In this study P450 arom gene (CYP19B) from carp (Cyprinus carpio) was cloned in order to obtain an useful diagnostic tool to better investigate endocrine disruption in the aquatic environment. The sequence of previously isolated aromatase genes in several teleosts was used to identify conserved sequence motifs, which were then used to design degenerate and specific PCR primers. These primers allowed the isolation of the CYP19B gene from carp. The gene has high sequence identity to similar genes from other fish species, but has particular sequence which is unique to this species. Preliminary RT-PCR data on tissues obtained on known EDCs exposed carps show that this detection system has high sensitivity
In vivo and in vitro exposures of carps to graded concentrations of endocrine disrupting chemicals
No full textThe objective of this study was to correlate morphological and biochemical
parameters of reproductive activity in fish exposed to graded concentrations
of endocrine disrupting chemicals. Two-year-old carps were exposed
for two weeks to graded concentrations of ethynyl-estradiol, tamoxifen, and
flutamide. For each chemical, morphological alterations of the gonads and liver
were described according to biomarker and sex steroid levels. In parallel, isolated
follicular cells (FCs) and testis fragments were incubated in the presence
or absence of carp pituitary homogenate and 25-hydroxycholesterol. Media
were analyzed for sex steroid level evaluations
In silico evaluation of PCB toxicity by integrative bioinformatics approach for food contaminants biomarker identification
No full textMany diseases are the outcome of a complex inter-relationship between multiple genetic and environmental factors. Research suggests that individual susceptibility is influenced more by certain genes than by exposure to environmental agents. The startup of Human genome project has induced the activation, by NIEHS, of a companion project: the Enviromental Genomic Project (EGP). The main goal of EGP is to better understand how individuals differ in their susceptibility to environmental agents and how these susceptibilities change over time,taking genetic variability into account. The new 'omics' technologies have enhanced the capability to massively screen thousand of genes or proteins at the same time. The capability to screen thousand genes at time allows to speed up the identification of biomarkers, not only as single molecule but also in their functional context (metabolic level). In this study we investigated, by using an integrated ‘in silico’ and ‘in vitro’ analysis, the possible use of biomarkers of exposure to Polychlorinated Biphenyls (PCBs) and Polycyclic Aromatic Hydrocarbons (PAHs) on multipotent preadipocites in a complex food matrix by using a double bioinformatics/genomics approach. Experimental data constitute the basic knowledge for ‘integrative bioinformatics’ analysis. In this study we have combined and analysed the results of two different data mining processes: 1) Bioinformatics data mining that has been performed on some publically available databases (PubChem, KEGG, PharmaKb). 2) Chemoinformatics data by screening the Chemical Abstract Systems. The results of two ‘in silico’ analysis has been used to rank food contaminant taking their preferential cellular and tissue target into account
Endocrine disrupting chemicals (EDC) with (anti)estrogenic and (anti)androgenic modes of action affecting reproductive biology of Xenopus laevis: Effects on gonad morphology
No full textA number of man-made chemicals has been shown to mimic endogenous hormones and to induce alterations of reproductive physiology in wild populations. Of particular importance are compounds that mimic estrogens and androgens (and their antagonists), because of their central role in reproductive function. In this study, male and female adult South African clawed toads (Xenopus laevis) were exposed to ethinylestradiol (EE2), tamoxifen (TAM), methyldihydrotestosterone (MDHT) and flutamide (FLU) as (anti)estrogenic and (anti)androgenic model compounds, respectively, at a concentration of 10(-8) M, and to water from the river Lambro (LAM), a contaminated watercourse from Northern Italy. Potential disrupting effects on reproduction were studied by histological analyses of gonads. The strongest adverse effects were observed in EE2 and LAM exposed males, e.g. tubule mean diameter reduction, spermatogenic nest breakdown and interlobular wall thickening. In both groups, the occurrence of small oocytes within the seminiferous tubules was observed. In TAM and MDHT exposed females slight oocyte atresia and occurrence of spermatogenic nests were observed. In contrast to previous studies addressing the alteration of molecular biomarkers in the same experimental setup, histological analyses of gonads were very sensitive and indicated an adverse effect of water from Lambro River on reproductive physiology of X. laevis
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