title: [Evolution of the concept of residues in the products of animals raised with the use of antibiotics].
abstract: The concept of residues of antibiotics used as feed additives or veterinary drugs in food producing animals is analysed, and implications on human public health are discussed. The examples of Tylosin and Penicillin are developed to illustrate the both notions of "high risk residue" and "toxicodisponibility" of residues. The "high risk residue" may be an active metabolite different by its chemical structure and by its pharmacological properties from the original drug administered. Slight modifications of the molecule, as the rupture of the beta lactam ring of the Penicillin, occuring in vivo, lead to a metabolite, e.g. penicilloyl group, that has lost all antibiotic activity but possesses allergenic potential. Toxicity of the residue, compared with that of the original drug, can then be modified or increased. On the other hand, such an active metabolite having a definite chemical structure, even if different from the original compound, can be present in the organism, either free or bound to serum or tissues proteins. Moreover, it is shown here, that in the case of a covalent binding of the drug or its metabolite (e.g. penicilloyl group) to serum albumin, the residues are mostly masked inside the tertiary structure of the albumin molecule, and are not accessible to antibodies. These different forms have then an effect upon the biodisponibility, the "toxicodisponibility", of the residues for the human consumer of animal products where they are present. These forms are only accessible with more and more specific and sensitive analytical methods which relates also the qualitative and quantitative notions of residue to the technological degree used for investigation, determination and identification. As to cooking techniques, they can lead to a thermodegradation of the residue or, on the opposite, to an unmasking of the residue present as a protein conjugate, e.g. penicilloyl-protein conjugate in milk.
mesh_terms: D000821:Animal Feed / Q000633:toxicity; D000818:Animals; D000900:Anti-Bacterial Agents; D002417:Cattle; D004342:Drug Hypersensitivity / Q000209:etiology; D005506:Food Contamination; D006358:Hot Temperature; D007700:Kinetics; D007933:Leucomycins / Q000009:adverse effects / Q000378:metabolism; D008892:Milk / Q000378:metabolism; D010406:Penicillins / Q000009:adverse effects / Q000378:metabolism; D051381:Rats; D012709:Serum Albumin / Q000378:metabolism; D013552:Swine
chemical_list: D000900:Anti-Bacterial Agents; D007933:Leucomycins; D010406:Penicillins; D012709:Serum Albumin
vernacular_title: Evolution du concept de résidu dans les produits animaux des antibiotiques utilisés en élevage.