Detection of oestrogen residues in meat by radioreceotor assay.

A radioreceptor assay, suitable for detecting residues in the meat of any compound with oestrogenic activity, is described. The assay is based upon the use of a purified preparation of oestrogen receptors obtained by affinity chromatography from swine uteri. The method was validated by measuring the oestrogenic activities in plasma and meat of diethylstilboestrol or oestradiol treated calves. The standard curve was performed by using oestradiol. Plasma levels of oestrogenic activity, expressed as equivalent of oestradiol, rose above control values 2 days after both diethylstilboestrol and oestradiol treatments, then declined to basal values by day 6 after the treatments. The levels of oestrogenic activity 10 days after treatment, found in the meat of diethylstilboestrol treated animals, were significantly higher than those found in control animals. No differences were found, however, between meat samples of control and oestradiol treated animals.