Effects of Combined Hypothyroidism and Selenium Deficiency on Selenoenzyme Glutathione Peroxidase Activity in Rats

• Published in: Acta veterinaria (Beograd) Vol. 74; no. 2; pp. 261 - 272
• Main Authors: Milanović, Svetlana, Valčić, Olivera, Kirovski, Danijela, Marinković, Darko, Vranješ-Đurić, Sanja, Gvozdić, Dragan, Jovanović, Ivan B.
• Format: Journal Article
• Language: English
• Published: Sciendo 01-06-2024
• Subjects: glutathione peroxidase; propylthiouracil; rats; selenium; thyroid hormones
• ISSN: 1820-7448; 1820-7448
• DOI: 10.2478/acve-2024-0018

The effects of propylthiouracil (PTU) treatment and selenium-deficient diet on selenium and thyroid status of Wistar male rats were examined in this study. Wistar male rats (n =128) were divided into four groups: (1) control group – selenium-adequate rats fed a diet supplemented with 0.334 mg Na selenite/kg feed and received regular drinking water (Se+PTU-); (2) selenium adequate rats fed a diet supplemented with 0.334 mg Na selenite/kg feed and received a dose of 150 mg/L of PTU in drinking water, (Se+PTU+); (3) selenium-deficient rats fed a diet containing 0.031 mg Na selenite/ kg and received regular drinking water (Se-PTU-); (4) selenium deficient rats fed a diet containing 0.031 mg Na selenite/kg and received 150 mg/L of PTU in drinking water (Se-PTU+). After three and seven weeks of treatment, all Se – animals had significantly lower whole blood Se concentrations and GPx1 and GPx3 activities. PTU induced a significant decrease in T4 and T3 plasma concentrations after three weeks of treatment in both PTU+ groups. Furthermore, after seven weeks, the T3 level was close to its detection limit in Se – animals. A negative correlation was spotted between GPx activity and concentration of T3 after three and seven weeks. It could indicate an inhibitory influence of thyroid hormones on the expression and/or activities of GPx enzymes related to the available Se in conditions of systemic decrease of T4 concentration. This effect was particularly pronounced in Se – animals.