COMBINING 2 INDEPENDENT INDIRECT METHODS AS A NEW POSSIBILITY FOR SCREENING THE ILLEGAL USE OF GROWTH PROMOTANTS

In this study the possibilities of combined indirect screening methods for the growth promotants clenbuterol and estradiol-17beta benzoate a nd the combination of both these agents were investigated. Three group s of 5 male goat kids (two months of age) were treated for 4 weeks; cl enbuterol per os, 10 mug/day/kg body weight via milkreplacer twice a d ay; 2 mg estradiol-17beta benzoate weekly per i.m. injection; combined clenbuterol per os + estradiol-17beta benzoate per injection. Five an imals were not treated and served as controls. Nuclear Magnetic Resona nce (NMR) was used as an initial tool to monitor the urine composition . The analysis of NMR spectra showed, that most treated animals had in creased L-lactate/creatine ratios (L/C-ratio) in their urine, compared to control animals. For screening, L-lactate/creatine ratios could be determined directly in urine - in a simple, quick and inexpensive man ner - by using enzymatic methods and an autoanalyzer. Histologically c lenbuterol induced degenerative changes in the urethral and glandular epithelium of the prostate. Changes consisted of vacuolization of the epithelium and necrosis with nuclear pyknosis and fragmentation. Estra diol-17beta benzoate induced metaplastic changes in the glandular tiss ue of the goat prostate. In combination with estradiol-17beta benzoate , characteristics of both agents could be observed. The histological m ethods and observed effects can be used directly for screening. The co mbination of independent histological and L/C-ratio methods looks very promising with respect to screening of growth promotants. Since in bo th cases effects of growth promotants are detected, it may be expected that this approach is not limited to goats or clenbuterol and estradi ol alone.