Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

Production of antibodies and incurred radiolabelled and unlabelled samples

A number of highly sensitive and in many cases highly specific antibodies have been successfully produced to 5 of the glucocorticoids. Although no single antibody can be regarded as "generic" it was considered unlikely at the commencement of the project that a single antibody with significant cross reactivity for all compounds could be raised. Cross reactivity profiles of the antibodies raised show that 2 antibodies could be used during final assay development to allow detection of all glucocorticoids included in the project.

Within the course of the project several calves were treated with synthetic glucocorticoids and slaughtered. Their tissues and fluids were collected and used for analysis. In a first study, nine calves were divided randomly into 3 equal groups. Prior to treatment blood and urine samples were collected for nine days.

Group A calves received dexamethasone, group B triamcinolone and group C methyl prednisolone. The three calves within each group received a single injection of glucocorticoid. Prior to slaughter blood and urine samples were taken daily. At slaughter plasma, serum, urine, bile, injection site, fat, kidney, liver, muscle and skin were collected. All samples were immediately frozen and stored at –20°C prior to transport to the project partners.

In a second study, four calves received four separate glucocorticoid treatments. Each calf received an intramuscular injection containing the relevant drug at a concentration of 10mg/50kg bodyweight. Calf 1 received two injections at 10mg/kg; one for each of the two drugs. Blood and urine samples were taken for three consecutive days prior to treatment and for two days after treatment. At slaughter plasma, serum, urine, bile, injection site, fat, kidney, liver, muscle and skin were collected. All samples were immediately frozen and stored at –20°C prior to transport to the project partners.

Incurred samples were prepared for use in both the screening and confirmatory ring tests. Six bovines were administered glucocorticoids then allowed a period of drug withdrawal prior to slaughter. Urine was collected from the experimental animals for 10 days prior to administration of the corticosteriods and throughout the withdrawal period. At slaughter liver, kidney and urine samples were removed and stored frozen until required.

At the end of the project a workshop was organised to disseminate the results achieved during the project to European national reference laboratories. At the workshop the results achieved were presented and practical demonstrations of the reporter gene assay and proteomics were given.

Contact

Chris ELLIOTT, (Head of unit)
Tél.: +44-1232-525679
Fax: +44-1232-525750
E-mail