RESUMO
Reserve regulations at El Palmar State Reserve, Yucatan, Mexico, prohibit the use of lead (Pb) shot, but hunters continue to use it, and no enforcement is implemented. Pb was quantified in sediments and in blue-winged teal Anas discors. No shot pellets were found in the sediment samples, nor were differences in sediment Pb concentrations observed within the reserve between popular hunting sites and those no longer used for hunting. However, there were differences between the hunting sites and sediments from an adjacent area where hunting is prohibited. Average Pb concentrations were highest at hunting entrances (15.69 ± 18.69 mg/kg) and lowest at decoy locations (5.24 ± 4.84 mg/kg). These averages are lower than the lowest effects level (31 mg/kg), although 10 samples exceeded this level. Pb-shot prevalence in gizzards was 4.88% (n = 41). Pb levels exceeded 5.0 mg/kg dry weight in one or more of the tested tissues (liver, gizzard, and bone) in 14 (34.14%; 7 female, 7 male; 11 adult, 3 juvenile) of the total birds. Bird weight, sex, and age had no effect on Pb concentration. Hunting using Pb shot in the reserve clearly affects Pb levels in sediments and in A. discors that winter there.
Assuntos
Patos/metabolismo , Exposição Ambiental , Sedimentos Geológicos/análise , Chumbo/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Osso e Ossos/metabolismo , Monitoramento Ambiental , Feminino , Moela das Aves/metabolismo , Chumbo/análise , Fígado/metabolismo , Masculino , México , Espectrofotometria Atômica , Poluentes Químicos da Água/análiseRESUMO
Poisoning of waterfowl due to ingestion of lead pellets is a worldwide problem in areas that are subject to hunting. No studies have assessed exposure of waterbirds to this heavy metal in Argentina, in spite of intense hunting activity, and the fact that only lead ammunition is commercially available. The objective of this study was to evaluate duck exposure to lead by examining gizzard and bone samples collected from 30 wild ducks, 16 Rosy-billed Pochard (Netta peposaca), and 14 Fulvous Whistling-Duck (Dendrocygna bicolor), provided by hunters in northern Santa Fe Province, Argentina, in July 2007. Radiographs, followed by dissection of the gizzards, showed that 31% of the Rosy-billed Pochards and 29% of the Fulvous Whistling-Ducks had ingested lead pellets (between one and four per animal). Lead in bone was found at concentrations associated with detrimental health effects. In spite of the small number of samples in this project, these results indicate high levels of lead exposure (both recent and chronic) in these species. This is the first report of a problem in Argentina that could represent a threat to the health and conservation of native aquatic species, their predators, and the wetlands they inhabit.
Assuntos
Doenças das Aves/induzido quimicamente , Patos , Intoxicação por Chumbo/veterinária , Chumbo/análise , Áreas Alagadas , Animais , Animais Selvagens , Argentina , Doenças das Aves/epidemiologia , Doenças das Aves/metabolismo , Osso e Ossos/química , Osso e Ossos/metabolismo , Exposição Ambiental , Feminino , Moela das Aves/química , Moela das Aves/metabolismo , Chumbo/metabolismo , Intoxicação por Chumbo/epidemiologia , Intoxicação por Chumbo/metabolismo , Masculino , Poluentes Químicos da Água/toxicidadeRESUMO
A homologous RIA for the determination of toxic gizzerosine activity in commercial fish meals has been developed. Three polyclonal antibodies (GR316, GR415, and GR418) were produced in female rabbits and extensively characterized for their potential use in individual RIA. The RIA had lower detection limits of 0.048, 0.78, and 0.39 ng/mg using the three respective antibodies. Because gizzerosine is derived from lysine and histidine, crossreactivity with these amino acids, and with histamine was examined. The antibodies crossreacted with histamine from 21 to 100%. No crossreactivity with histidine or lysine was observed for any of the three antibodies. Antibody GR415 was chosen for determination of gizzerosine in extracted fish meal samples because crossreactivity of histamine using this antibody was only present at high concentrations, and the Ka value for gizzerosine was 10-fold greater than for histamine. A mild buffer extraction procedure was used, resulting in 98% gizzerosine recovery. Displacement curves from extracted and serially diluted fish meal samples were parallel with gizzerosine standard. Inter-and intra-assay coefficients of variation were 11 and 15%, respectively. We used the RIA for determination of gizzerosine activity in a pool of 23 fish meal samples of known gizzerosine scores (determined with a chick bioassay), and histamine content. The partial correlation coefficient between gizzerosine content determined by the RIA and gizzerosine scores from the bioassay was high (0.83), and significant (P < 0.01). There were also significant correlations between gizzerosine scores and histamine content of the fish meals (0.63, P < 0.01), and between histamine content and gizzerosine levels determined by the RIA (0.59, P < 0.01). The application of the homologous RIA for the determination of gizzerosine activity in commercial fish meals could be of importance for the prevention of gizzard erosions in the poultry industry, and for studying gizzerosine-induced pathology and metabolism.
Assuntos
Galinhas/metabolismo , Produtos Pesqueiros/análise , Imidazóis/análise , Animais , Anticorpos/imunologia , Anticorpos/metabolismo , Ligação Competitiva , Reações Cruzadas , Feminino , Moela das Aves/metabolismo , Moela das Aves/patologia , Histamina/imunologia , Histamina/metabolismo , Histidina/imunologia , Histidina/metabolismo , Imidazóis/imunologia , Imidazóis/farmacologia , Radioisótopos do Iodo , Lisina/imunologia , Lisina/metabolismo , Doenças das Aves Domésticas/patologia , Doenças das Aves Domésticas/prevenção & controle , Coelhos , Radioimunoensaio/métodos , Radioimunoensaio/veterinária , Sensibilidade e Especificidade , Estatística como AssuntoRESUMO
A study about the genesis of the inner lining which covers the mucous membrane of the chicken gizzard was made and histochemical test were employed to detect the presence of carbohydrate in the epithelial components of the mucous membrane. The histochemical treatment of the apical border of gizzard epithelium from the 5th, 7th, 9th, 12th, and 15th d of incubation revealed the absence of glycoprotein (with 1.2-glycol containing hexoses), sialic acid, and glycogen but weakly acidic sulphated mucosubstances were present. The same was observed in the medium 1/3 of the gizzard epithelium on 12th and 15th d. The upper 1/3 of the buddings, precursor of gizzard glands, on the 15th d, besides exhibiting the same histochemical characteristics of apical border, revealed, clearly visible, strongly sulphated mucosubstances. The histochemical reactions of the epithelium which covers the free surface and lines the pits from the 18th d of incubation and from the young chicken (0.5 h, 1 d, 3 d, 7 d, 3 weeks and 8 weeks) revealed the absence of glycoprotein (with 1.2-glycol containing hexoses), sialic acid, and glycogen, however, weakly acidic sulphated mucosubstances and strongly sulphated epithelial acidic mucin were present. On the 18th d, the glands presented a lumen and the accumulation of intraepithelial secretion displaced the upper part of the superficial epithelium, splitting, it.