Protective Effect of Paricalcitol on Doxorubicin-Induced Thyroid Dysfunction in Rats

The present study aimed to examine the effect of vitamin D receptor agonist paricalcitol (PRC) on doxorubicin (DOX)-induced thyroid gland damage in rats. Twenty-eight Wistar rats were randomly categorized into four groups: (1) control (SF; 2 ml/kg); (2) DOX (18 µg/kg), (3) PRC (0.5 μg/kg) and (4) PRC (1 μg/kg). PRC was administered three times a week for 21 days. In PRC and 18 µg/kg DOX groups, drugs were administered on the 19th, 20th or 21st days of the experiment. On the 22nd day, 99mTc pertechnetate uptake level and serum biochemical parameters were determined. 99mTc pertechnetate uptake was lower in groups receiving DOX and/or 0.5 and 1 μg/kg PRC than in control groups. The 99mTc pertechnetate levels in the 0.5 and 1 μg/kg PRC groups were significantly higher than the DOX group. However, PRC pretreatments decreased 99mTc pertechnetate uptake in rat thyroid gland. Besides, DOX caused a significant increase in blood TSH levels and decreases in T3 and T4 levels compared to the control groups. Administration of PRC decreased TSH level and increased T3 and T4 levels compared to DOX group. PRC administration protects thyroid gland against DOX-induced toxicity.