IlLEGAL USE OF GROWTII PROMOTING AGENTS AND ALTERATIONS IN BOVINE FEMALE REPRODUCTIVE SYSTEM

Introduction· The P1-agonist clenbuterol is a drug that finds wide application in. veterinary medicine as . bronchodilator and tocolytic agent. In recent years, ìt has been more and more utiIized as repartitioning agent to improve the performance of meat animals. In faci. clenbuterol long-term administration improves growth rate, reduce fat deposition and increase protein accretion in cattle, pigs and poultry. From this point of view, clenbuterol treatment should fulfil producers and consumers demands (1). Thus, in Italy, veal calves are reasonably suspected to be systematically treated with P-agonists in order to stimulate growth. Nevertheless, a field study carried out on 423 regularly slaughtered veal calves. revealed a ratber constant involvement of the female genital tract consisting in anatomical and histopathological changes associated with biochemicallesions (23). The alterations present in the female reproductive system of veal calve s, sequestrated by the Judicial Authority for illegal treatment with clenbuterol, were investigated. In the urine of six male belonging to the same herd, clenbuterol were found in not allowed amounts. Materials and methods The histological investigations were performed on the uteri, ovaries and major vestibolar glands of 15 crossbred veal calves, 2-4 months old. Tissue samples were fIxed in buffered formalin (10%) and tben paraffIn-wax embedded sections were stained by routine methods (Haematoxilin-eosin, Van Gieson, Azan, Pas-reaction). Major vestibolar glands were processed using more specifIc techniques (Alcian-Pas pH 2.6 and Alcian pH 1). Just after slaughtering, tissue samples (about 1 g) were dissected from the vagina (A), the body (B), and the uterine horns (C) and then frozen at -80"C in order to assay cytosolic estrogen and progesterone receptor concentrations using a modified dextrancoated charcoal method (3). The results obtained by the Scatchard analysis, are expressed as femtomoles of specifIcally bound hormone per mg of protein (mean values±S.E.M.). The hormonal status, was evaluated on serom samples obtained from clotted blood drawn from the jugular vein of each animaI. Estradiol and progesterone serom level were measured using RIA techniques (Estradiol Double Antibodl and Progesterone Coat-A-CountO DPC Los Angeles, USA). ----,1 Results The lumen of the vagina and of the uteros was constantly filled with an abnormal collection of transparent mucus, and in all examined animals r----· l microcystic ovaries were presento From the histological point of view, the cervical part of the uteros showed pluristratification of the endometrial epithelium, frequently associated with squamous metaplasia of the inner layer. In the oldest calves, glandular hyperplasia and hypersecretion were detected. Endometrial cysts were also presento The major vestibular glands showed hyperplasia of ductal and glandular epithelium with ectasic lumina filled with ·0 I I J~~P~w_...I._~~~-L~~~' t Pas positive or Alcian-Pas positive material; r scattered foci of mononuclear cells and metaplastic transformation were occasionally found. In the ovaries, atretic tertiary folli cles associated witb normal ones were seen. The number of uterine estrogen and progesterone receptors reached high concentrations mainly in tbe Figure 1. Uterine estrogen and progesterone uterine body (B) and horns (C) (estrogenreceptor concentrations (mean values±S.E.M.) receptors, B: 480± 98, C: 487 ± 130; progesterin veal calves. A=vagina, B=body, C=horns one receptors, B: 632 ± 118, C: 1137 ± 292). In (n= 15) the vagina (A) only the estrogen receptors are particularly elevated (A: 123+22), whereas progesterone receptor levels are normal (Fig. 1). RIA investigations revealed that neitber traces of estradiol nor progesterone were present in the examined sera. 424 Diseussion The histological pictures, reveal a morphological and physiological status incompatible with the immature age of the animals. On the other hand, these findings suggest a condition of exogenous stimulation by growth-promoting or anabolic agents. Moreover, the high concentrations of estrogen and progesterone receptors at uterine level, when compared with normal values (4), also indicate an abnormal disposition of the receptorial status. It is well established that estrogenic treatments induce steroid receptors syntesis, but recently, clenbuterol treatment has been related with uterine estrogen and progesterone receptors increase in rat and pigs (5), without affecting or at least inhibiting hormonal serum levels. Reterences 1. VanbeHe M., 1990, New technology governing nutrient partÌtioning in meat animals. Atti Conf. Int. Sanita Prod. Bovina Mediterraneo, 1, 459. 2. Girardi C., Badino P., Re G., Dacasto M., Biolatti 8., Brusa F., Di Carlo F., 1990, Stato recettoriale e reperti anatomo ed istopatologici del tratto genitale femminile in vitelli a carne bianca. Atti Soc. Il. Buiatria, 22, 375. 3. Di Carlo F., Racca S., Conti G., Gallo E., Muccioli G., Sapino A., Bussolati G. 1984, Effeets of long-term administration of high doses of medroxyprogesterone aeetate on hormone receptors and target organs in the female rat. J. Endocr. 103, 'll37. 4. Re G., Badino P., Conti G., Dacasto M., Di Carlo F., Girardi c., 1989, Distribution of eytoplasmic estrogen (ER) and progesterone (PgR) receptors in bovine genital traet. Pharmaool. Res., 21, suppl.1, 79. 5 Re G., Badino P., Tartari E., Biolatti B., Di Carlo F., Girardi C., 1990, Clenbuterol long-term administration in fmishing female pigs. Note 1: effeets on oestrogen and progesterone receptor distribution and ooncentration in genital tract. Schweiz. Arch. Tierheilk., 132, 455.