Studies on the Physiological Relationship between Thyroid Hormones, Serum Lipid Profile and Erythrocyte Antioxidant Enzymes in Clinically Healthy Iranian Fat-tailed Sheep

The aim of the present study was to determine whether there was any correlation between serum thyroid hormones, lipids, lipoproteins and the activities of erythrocyte superoxide dismutase (SOD) and glutathione peroxidase (GPX) in adult nonpregnant uniparous Iranian pure bred fat-tailed ewes. Blood samples (10 mL) were taken from the jugular vein of 30 clinically healthy Iranian adult nonpregnant uniparous ewes at 8 a.m during 6 consecutive days of summer with a mean ambient temperature of 40°C. The serum was analyzed for thyroxine (T4), tri-iodothyronine (T3), free thyroxine (fT4), free tri-iodothyronine (fT3), cholesterol, triglyceride, lipoproteins [high density lipoprotein (HDL-cholesterol), low density lipoprotein (LDL-cholesterol) and very low density lipoprotein (VLDL-cholesterol)], SOD and GPX activity. There were no significant differences in serum thyroid hormones, lipids, lipoproteins and antioxidant enzymes in different days (P>0.05). In addition, there were no significant correlations between serum thyroid hormones, lipids, lipoproteins and antioxidant enzymes in different days (P>0.05).