Total Radioactive Residues and Residues of [36Cl]Chlorate in Market Size Broilers
详细信息 查看全文
- 作者：David J. Smith ; James A. Byrd ; Robin C. Anderson
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2007
- 出版时间：July 11, 2007
- 年：2007
- 卷：55
- 期：14
- 页码：5898 - 5903
- 全文大小：61K
- 年卷期：v.55,no.14(July 11, 2007)
- ISSN：1520-5118
文摘
The oral administration of chlorate salts reduces the numbers of Gram-negative pathogens ingastrointestinal tracts of live food animals. Although the efficacy of chlorate salts has beendemonstrated repeatedly, the technology cannot be introduced into commercial settings without firstdemonstrating that chlorate residues, and metabolites of chlorate remaining in edible tissues, representa negligible risk to consumers. Typically, a first step in this risk assessment is to quantify the parentcompound and to identify metabolites remaining in edible tissues of animals treated with theexperimental compound. The objectives of this study were to determine the pathway(s) of chloratemetabolism in market broilers and to determine the magnitude of chlorate residues remaining in edibletissues. To this end, 12 broilers (6 weeks; 2.70 ± 0.34 kg) were randomly assigned to three treatmentsof 7.4, 15.0, and 22.5 mM sodium [36Cl]chlorate dissolved in drinking water (n = 4 broilers pertreatment). Exposure to chlorate, dissolved in drinking water, occurred at 0 and 24 h (250 mL perexposure), feed was withdrawn at hour 38, water was removed at hour 48, and birds were slaughteredat hour 54 (16 h after feed removal and 8 h after water removal). The radioactivity was rapidlyeliminated in excreta with 69-78% of the total administered radioactivity being excreted by slaughter.Total radioactive residues were proportional to dose in all edible tissues with chloride ion comprisinggreater than 98.5% of the radioactive residue for the tissue (9.4-97.8 ppm chlorate equivalents).Chlorate residues were typically greatest in the skin (0.33-0.82 ppm), gizzard (0.1-0.137 ppm),and dark muscle (0.05-0.14 ppm). Adipose, liver, and white muscle tissue contained chlorateconcentrations from 0.03 to 0.13 ppm. In contrast, chlorate concentrations in excreta eliminated duringthe 6 h period prior to slaughter ranged from 53 to 71 ppm. Collectively, these data indicate thatbroilers rapidly convert chlorate residues to an innocuous metabolite, chloride ion, and that chlorateresidues in excreta remain fairly high during the time around slaughter. Because the target tissue ofchlorate is the lower gastrointestinal tract, the relatively high distribution of parent chlorate to inediblegastrointestinal tissues and low distribution to edible tissues is favorable for the biological activityand for food safety considerations. These data, when used in conjunction with a toxicologicalassessment of chlorate, can be used to determine a likely risk/benefit ratio for chlorate.