engleski

Relationship between clenbuterol residues in pig liver and choroid/pigmented retinal epithelium after repeat administration in a growth-promoting dose

Previous studies have shown persistent accumulation of the beta2-adrenergic agonist clenbuterol in retinal tissue due to its interaction with the pigment melanin, whereby its retinal concentration significantly exceeded that found in bovine liver. The aim of the present study was to investigate the relationship between persistence of clenbuterol residues in pig liver and choroid/pigmented retinal epithelium (choroid/PRE) after repeat administration in a growth-promoting dose. The study was carried out in 18 male pigs (15 treated and 3 controls) of a known breed, aged 90 days, body mass 50 kg, farm-bred, and kept under the same hygienic conditions. A growth-promoting dose of clenbuterol (20 μ g/kg body mass per day) was administered orally to pigs for 28 days. Upon cessation of administration, on days 0, 3, 7, 14 and 35, the pigs were randomly sacrificed, and the liver and choroid/PRE, previously dissected from the eye, were collected and stored at -25 0C until analysis. The enzyme-linked immunosorbent assay (ELISA) was used as a screening method, and reverse phase liquid chromatography-electronspray ionization tandem mass spectrometry (LC-ESI/MS/MS) as a confirmation method for residual clenbuterol in pig liver and choroid/PRE tissues. Study results showed the ratio of choroid/PRE to liver clenbuterol concentration to increase upon clenbuterol discontinuation, yielding mean values of 17:1, 27:1, 52:1, 145:1 and 155:1 on days 0, 3, 7, 14 and 35, respectively. These findings indicated a very high potential of clenbuterol accumulation in choroid/PRE, along with slow depletion relative to liver tissue, suggesting the pig choroid/PRE to provide a powerful tool for reliable and effective control of residual clenbuterol to detect its abuse in pig products intended for human consumption.

clenbuterol; pig; liver; choroid/pigmented retinal epithelium

nije evidentirano