engleski

Depletion of β 2-adrenergic agonist clenbuterol as growth promoter in pigmented tissues of pigs according to days of withdrawal

Clenbuterol is a xenobiotic, orally active β 2-adrenergic agonist that might be abused as a growth promoter in food animals. Previous studies have indicated sequestration of clenbuterol in pigmented bovine tissues such as retina and more recently in hair due to its interaction with the pigment melanin. The aim of the study was to investigate clenbuterol residue depletion in male pig hair and choroid/pigmented retinal epithelium (choroid/PRE) on days 0, 3, 7, 14 and 35 upon subchronic (28 days) exposure to an oral growth-promoting dose. The results obtained by use of previously validated methods of enzyme-linked immunosorbent assay (ELISA) and liquid chromatography tandem mass spectrometry (LC-MS/MS) showed the concentration of clenbuterol to be highest in choroid/PRE (503.74&plusmn ; ; 27.44 ng/g), followed by hair (203.84&plusmn ; ; 76.79 ng/g) on day 0, to gradually decrease to 38.20&plusmn ; ; 1.66 ng/g and 41.49&plusmn ; ; 10.47 ng/g on day 35 of withdrawal, i.e. approximately 76-fold and 83-fold maximal allowed concentration of 0.5 ng/g for liver as edible tissue, respectively. Study results suggested the very high accumulation potential of these pigmented tissues for clenbuterol to be associated with the slow depletion behavior of the substance, pointing to these tissues as appropriate matrices to detect clenbuterol abuse even after a prolonged time of withdrawal.

clenbuterol; depletion; pig; hair; choroid/pigmented retinal epithelium

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