Liver Of Male Fish Research Articles

Long-Term Exposure to Neonicotinoid Insecticide Acetamiprid at Environmentally Relevant Concentrations Impairs Endocrine Functions in Zebrafish: Bioaccumulation, Feminization, and Transgenerational Effects.

Neonicotinoid insecticides have attracted worldwide attention due to their ubiquitous occurrence and detrimental effects on aquatic organisms, yet their impacts on fish reproduction during long-term exposure remain unknown. Here, zebrafish (F0) were exposed to a neonicotinoid, acetamiprid, at 0.19-1637 μg/L for 154 d. Accumulation and biotransformation of acetamiprid were observed in adult fish, and the parent compound and its metabolite (acetamiprid-N-desmethyl) were transferred to their offspring. Acetamiprid caused slight survival reduction and significant feminization in F0 fish even at the lowest concentration. Hormone levels in F0 fish were remarkedly altered, that is, gonad 17β-estradiol (E2) significantly increased, while androstenedione decreased. The corresponding transcription of steroidogenic genes (ar, cyp19b, fshβ, gnrh2, gnrh3, and lhβ) were significantly upregulated in the brain and gonad of the females but downregulated in the males. The vtg1 gene expression in the liver of male fish was also upregulated. In addition to F0 fish, parental exposure to acetamiprid decreased hatchability and enhanced malformation of F1 embryos. Chronic exposure to acetamiprid at environmentally relevant concentrations altered hormone production and the related gene expression of the hypothalamic-pituitary-gonad (HPG) axis in a sex-dependent way, caused feminization and reproductive dysfunction in zebrafish, and impaired production and development of their offspring.

Antagonistic interaction between perfluorobutanesulfonate and probiotic on lipid and glucose metabolisms in the liver of zebrafish.

Perfluorobutanesulfonate (PFBS) and probiotic bacteria can interact to induce hepatic hypertrophy. However, the molecular events occurring in the hypertrophic liver are still unknown. Therefore, we performed this follow-up study using adult zebrafish that were exposed for 40 days to 0 and 10μg/L PFBS, with or without dietary supplementation of probiotic Lactobacillus rhamnosus. After PFBS or/and probiotic exposures, proteome perturbation, histological pathogenesis and glucose metabolism were investigated in the livers. Proteomic analysis showed potent intervention of PFBS or/and probiotic with hepatic functions. PFBS single exposure caused marked disturbances in lipid metabolisms, which may underlie the severe vacuolization in male liver. The addition of probiotic alleviated the lipid metabolic disorders of PFBS. Furthermore, probiotic supplementation enhanced ATP energy production using glucose in mitochondrial respiratory chain of male fish. However, PFBS alone caused remarkable increase in blood glucose level (by 2.5-fold relative to the control), underlining the onset of hyperglycemia symptom. In contrast, the liver of male fish from the coexposure group functioned appropriately, which immediately increased insulin levels by 2.2-fold to reduce the glucose accumulation in blood. In female liver, PFBS alone significantly decreased the blood glucagon concentration by 2.9-fold. The deficiency of glucagon hormone consequently contributed to the accumulation of glycogen (3.2-fold) therein. Vigorous antagonistic interaction between PFBS and probiotic was noted with respect to glucose metabolism, which restored ATP, glucose, glycogen and glucagon to the control levels. Overall, the present study finds that probiotic L. rhamnosus is efficient to mitigate the metabolic disorders of PFBS on lipid and glucose, highlighting the potential values of probiotic bacteria to protect the aquatic ecosystem.

Reproductive disruption in lambari Astyanax fasciatus from a Southeastern Brazilian reservoir

The aim of this study was to assess the health indicators and reproductive endpoints in a wild population of lambari Astyanax fasciatus, a small characid fish widely distributed in South America. A range of biomarkers, from the molecular to population levels, was evaluated in adult fish sampled from five sites from the Furnas Reservoir, Grande River. At the sites that receive untreated agriculture and industrial residues, fish showed reduced body size and delayed gonadal maturation. Fish from the sites located immediately downstream from the municipal wastewater discharges exhibited feminisation, intersex and evidence of contamination by xenoestrogens. Elevated levels of zona radiata proteins were found by Western blot in the livers of male fish from three contaminated sites. Overall, this study provides the first evidence of endocrine disruption in a wild fish population inhabiting the Furnas Reservoir, and suggests water contamination by oestrogenic compounds and agricultural residues with a possible risk to human health and wildlife.

Identification and characterization of estrogen-responsive gene products in the liver of rainbow trout.

Injection of male rainbow trout with estradiol induced the production of a major serum protein, vitellogenin (VG), of molecular weight (MW) 170 000. This protein is immunoprecipitable by an antiserum raised against lipovitellin from the eggs. Labelling by incubation of liver cubes of estradiol-treated fish with [35S]methionine and analysis of immunospecific products showed incorporation into two polypeptides of MW 170 000 and 160 000. The peptide patterns generated from these two polypeptides by Staphylococcus aureus V8 protease digestion were identical. Cytoplasmic poly(A)+ RNA of estradiol-treated male liver directs the synthesis of a polypeptide of 160 000 daltons in the reticulocyte cell-free protein-synthesizing system or in Xenopus oocytes. This polypeptide is chemically, immunologically, and electrophoretically identical to the authentic VG polypeptide of 160 000 daltons. Changes in mRNA populations in the liver of male fish following estradiol treatment were detected on gels and by hybridization. On methylmercuric hydroxide gels, a polyadenylated RNA species of about 6300 nucleotides was found in estradiol-treated fish which was absent from the control fish. Data from R omicron t analysis revealed the presence of at least two mRNA sequences of the high frequency class in the RNA of hormone-induced fish and their sizes were determined by Northern blot analysis to be 6300 and 1800 nucleotides, respectively. These observations are consistent with the induction of vitellogenins and at least another estrogen-responsive gene product by estradiol as reported in other egg-laying vertebrates.

A New Microsporidian Parasite from the Golden Shiner, Notemigonus crysoleucas

A new species of microsporidian (sporozoan) parasite from the ovaries of the golden shiner (Notemigonus crysoleucas) from southern Illinois is described. The name Plistophora ovariae n. sp. is suggested. Fresh spores are ovoid or ellipsoid and measure 8.42±0.17 by 4.24±0.15 microns for spore length and width, respectively. The primary site of infection is in the ovary, but the parasite is occasionally found in the liver and kidney of female fish. The parasite is not found in either the testis, kidney, or liver of male fish. The importance of this parasite to the bait industry is suggested, as it reduces fecundity and is suspected of causing sterility in older female brood fish. The parasite is of wide distribution, occurring in commercial bait hatcheries in Missouri, Arkansas, and Kentucky, as well as in Illinois.