Effect of Temperature Stress on Thyroid Functions in Normal Adult Rats

The thyroid gland is an endocrine gland that secretes among other hormones; triiodothyronine (T3) & tetraiodothyronine (T4) that play a pivotal role & critical in the regulation of body temperature (Tb), stimulation of thermogenesis, & regulation of cellular metabolism. T3 and T4 are hormones that support & maintain the metabolism of animals & since metabolism always generates heat, T3 & T4 increased bioactivity has an effect on the core body temperature. The available literature on the effect of temperature on the thyroid gland in Sub Sahara Africa is limited to humans & yet there are some differences between humans & other mammals. For example, human sweat & hardly covered with fur. This study, therefore addressed the effect of exposure to extreme heat & cold on the thyroid functions in normal adult rats. The purpose of the study was to assess the effect of temperature stress on the thyroid functions & core body temperatures. Sixty rats were divided into three treatment groups of 20, for heat stress, cold stress & control treatments, respectively. In each group three rats were from the same litter to minimise the effect of genetic variation on thyroid function.