Faculty of Veterinary Medicine University of Zagreb
Abstract
Crop residues are rich in thiourea content, on account of the indiscriminate use of thiourea as a fertilizer. It is interesting to investigate the impact of thiorea feeding on liver and kidney functions in adult sheep. Experimental hypothyroidism was induced by per os feeding of thiourea to nine adult Marwari rams. Prior to the start of the trial, plasma levels of thyroxin (T4), thyroid stimulating hormone (TSH), alkaline Phosphatase (ALP), Aspartate aminotransferase (AST), alanine amminotransferase (ALT), glucose, protein, A/G ratio, BUN and creatinine were assessed to establish control values. The clinical profile of the rams and evaluation of the above parameters were conducted on Days 3, 5 and 7 post thiourea feeding. At the end of the experiment a decrease in respiration, heart rate, temperature and feed intake were observed. A significant fall in T4 and glucose was observed on day 7, whereas a significant increase in TSH, ALP, AST and ALT were observed. The elevation in protein, BUN and creatinine concentrations was not much significant. The altered hormone profile revealed the hypofunction of the thyroid gland. The increased concentration of enzymes revealed bile duct hyperplasia, damage to hepatocytes and the biliary network. Further, a shift in metabolic profile suggested low energy intake and depressed growth. In conclusion, thiourea feeding induces hypothyroidism, generalized oxygen starvation at tissue level and disturbs hepatic and renal functions.Žetvene kulture sadrže ostatke tioureje, zbog njezine nerazborite uporabe kao gnojiva. Zbog toga je bilo vrijedno istražiti utjecaj dodataka tioureje na funkciju jetre i bubrega u odraslih ovaca. Hipotireoidizam je bio pokusno izazvan peroralnim davanjem tioureje u devet odraslih ovnova pasmine Marwari. Prije početka pokusa određene su kontrolne vrijednosti razina tiroksina (T4) u plazmi, tireostimulirajućeg hormona (TSH), alkalne fosfataze (ALP), aspartat-aminotransferaze (AST), alanin-aminotransferaze (ALT), glukoze, proteina, omjera A/G, ureje i nitrata u krvi (BUN) te kreatinina. Klinički nalaz u ovnova i prosudba navedenih pokazatelja razmatrani su 3. 5. i 7. dana nakon davanja tioureje. Na kraju pokusa ustanovljena je smanjena frekvencija disanja, smanjeni broj otkucaja srca, tjelesna temperatura i smanjeno uzimanje hrane. Značajan pad razine T4 i glukoze zapažen je 7. dana nakon davanja, dok su se vrijednosti za TSH, ALP, AST i ALT značajno povećale. Povećanje koncentracije proteina, BUN i kreatinina nije bilo signifikantno. Promjene u sadržaju hormona upućuju na hipofunkciju štitnjače. Povećana koncentracija enzima upućuje na hiperplaziju žučovoda, oštećenje hepatocita i žučovodne mreže. Nadalje, promjene u metabolizmu govore o smanjenom unosu energije i smanjenom rastu. Zaključno se može reći da davanje tioureje u hrani dovodi do hipotireoidizma, općeg nedostatka kisika u tkivima i poremećaja funkcije jetre i bubrega
