The effects of long term handling stress on thyroid function in male rats

Abstract

Inappropriate responsiveness of the stress system may cause numerous alterations in endocrine, metabolic and autonomic systems. Many studies have been carried out on the effects of acute stress on thyroid function but the effects of chronic stress have not been fully investigated. The purpose of this study is to evaluate the effects of long term handling stress on thyroid function. Study was performed on two groups of male Wistar rats. Experimental group received distilled water by oral tube for two months once a day, while control group were not handled or did not received distilled water. At the end of the period animals were anesthetized, abdomen was opened and blood samples were obtained from abdominal aorta. The samples were centrifuged, sera separated and stored at – 20 ?C until the time of the assay. Total triiodothyronine (TT3), total thyroxine (TT4), free triiodothyronine (FT3), free thyroxine (FT4) and T3 uptake were assayed by ELISA and thyroid stimulating hormone (TSH) was determined by radio-immunoassay using DRG kits. Total T4 level was significantly lower in experimental group (3.49 ± 0.1 ?g/dl) than in control groups (4.5 ± 0.34). Free T3, free T4 and T3 uptake were also significantly lower in experimental group (P