ORIGINAL PAPER The relationship between serum level of thyroid hormones, trace elements and antioxidant enzymes in dromedary camel (Camelus dromedarius) S. Nazifi & M. Mansourian & B. Nikahval & S. M. Razavi Accepted: 28 March 2008 # Springer Science + Business Media B.V. 2008 Abstract Thyroid hormones might be able to regu- late the activities of superoxide dismutase (SOD), catalase and glutathione peroxidase (GPX). The role of thyroid hormones in metabolic pathways and antioxidant enzyme activities are well known in many species. Nevertheless, there is no report describing probable relationship between thyroid hormones status, erythrocyte antioxidant enzymes and serum profiles of trace elements. This study was undertaken to investigate the relationship between these parame- ters in Iranian dromedary camels. Blood samples were taken from the jugular vein of 30 clinically healthy Iranian dromedary camels under aseptic conditions during 6 consecutive days of summer. The serum was analyzed for serum profile of thyroid hormones, trace elements, SOD and GPX activity. There were no significant differences in serum thyroid hormones, serum level of zinc (Zn), copper (Cu), manganese (Mn), iron (Fe), selenium and antioxidant enzymes in different days (P>0.05). There was a significant negative correlation between SOD and Fe (P<0.01, r=-493). There was no significant correlation between other parameters. In case of copper deficiency likewise the present study, the copper was used to produce more SOD, so there was a decrease in Fe transportation, and it might be a cause of decrease in Fe amount. On the other hand, a relatively small quantity of Fe is present in tissue myoglobin, catalase, peroxidases, and cytochromes. So it might be another cause of decrease in Fe amount. The explanation for these finding is not possible at this moment and further investigations are needed to interpret these changes. Keywords Antioxidant enzymes . Thyroid hormones . Trace elements . Dromedary camel (Camelus dromedarius) Abbreviations SOD superoxide dismutase GPX glutathione peroxidase Zn zinc Cu copper Mn manganese Fe iron Trop Anim Health Prod DOI 10.1007/s11250-008-9167-9 S. Nazifi (*) Department of Clinical Studies, School of Veterinary Medicine, Shiraz University, Shiraz 71345–1731, Iran e-mail: nazifi@shirazu.ac.ir M. Mansourian : B. Nikahval Department of Veterinary Medicine, Islamic Azad University of Bojnourd, Bojnourd, Iran S. M. Razavi Department of Pathobiology, School of Veterinary Medicine, Shiraz University, Shiraz, Iran