کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5799480 | 1111803 | 2011 | 6 صفحه PDF | دانلود رایگان |
The aim of this study was to determine if topical application of dexamethasone affected the serum concentrations of thyroid hormones (triiodothyronine T3 and thyroxine T4), glucose, triglycerides, total protein and insulin in normal horses. Ten horses were treated twice daily for 10Â days with 50Â g dexamethasone using an ointment formulation. Thyroid hormones and insulin were assayed using standard radioimmunoassay methods, while glucose, triglycerides and total protein were determined using a standard enzymatic method and the Biuret reaction, respectively.An increase in serum glucose and triglyceride concentrations was accompanied by 2-6-fold increases in serum insulin concentrations, but there was no change in serum total protein concentration. Insulin secretion increased with concomitant hyperglycemia and hypertriglyceridemia. A non-significant decline in T4 secretion was noted. Serum T3 and T4 concentrations declined continuously below baseline values from 48Â h. Glucose and insulin levels returned to baseline values 3Â days after treatment withdrawal, whereas triglycerides reverted to baseline by 7Â days. In contrast, baseline values of serum T3 and T4 were not reached by 20Â days following drug withdrawal. The results indicated that topical administration of dexamethasone affected thyroid function and physiological metabolic functions, which may have implications for potential doping cases in racing horses.
Journal: The Veterinary Journal - Volume 188, Issue 3, June 2011, Pages 307-312