title: Determination of clenbuterol residues in retinal tissue of food-producing pigs.
abstract: The aim of the present study was to assess the persistence of clenbuterol residues in retinal tissue of pigs after repeated administration in a growth-promoting dose, using enzyme-linked immunosorbent assay (ELISA) as a screening method for quantitative determination. A growth-promoting dose of clenbuterol (20 μg/kg body mass per day) was administered orally to the experimental group (n = 6) for 21 days, whereas control animals (n = 3) were left untreated. Clenbuterol-treated pigs were randomly sacrificed (n = 3) on days 0 and 45 of treatment discontinuation, and clenbuterol residues were determined in retinal tissue dissected from the eye. ELISA was found to be acceptable for quantitative determination of clenbuterol in retinal samples because previous method validation yielded mean recovery values of 84.3-96.5% with variation coefficients < 14%. The mean (± SD) retinal clenbuterol concentration was 1874 ± 114 ng/g immediately upon clenbuterol withdrawal (day 0) and 73 ± 4 ng/g on the last day post-withdrawal (day 45). Study results pointed to a very high potential of clenbuterol accumulation in retinal tissue and marked persistence of clenbuterol residues upon anabolic dose administration, suggesting retinal tissue to be a very useful matrix for effective control of residual clenbuterol in food-producing pigs.
authors.affiliation: Laboratory for Analytical Chemistry, Croatian Veterinary Institute, Savska 143, 10 000 Zagreb, Croatia. pleadin@veinst.hr
authors.forename: Jelka
authors.initials: J
authors.lastname: Pleadin
authors.forename: Ana
authors.initials: A
authors.lastname: Vulić
authors.forename: Mario
authors.initials: M
authors.lastname: Mitak
authors.forename: Nina
authors.initials: N
authors.lastname: Perši
authors.forename: Dinka
authors.initials: D
authors.lastname: Milić
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002976:Clenbuterol / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D004350:Drug Residues / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay; D008297:Male; D011897:Random Allocation; D012160:Retina / Q000737:chemistry*; D034421:Sus scrofa; D014018:Tissue Distribution
chemical_list: D002976:Clenbuterol