A. Lommen et Mj. Groot, COMBINING 2 INDEPENDENT INDIRECT METHODS AS A NEW POSSIBILITY FOR SCREENING THE ILLEGAL USE OF GROWTH PROMOTANTS, Journal of veterinary medicine. Series A, 40(4), 1993, pp. 271-282
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.