STUDY OF THE EFFECTS OF PENTACHLOROPHENOL ON THYROID GLAND IN ALBINO RATS

Abstract

The results of the study revealed that there was significant decrease in tri-iodo thyronine (T,) and tetra-iodothyroxine (T,) in PCP treated group which was dose and duration dependent. This decrease could be attributed to vacuolation and depletion of the colloid in the thyroid acini which was proved histologically in the study. Histological examination of the thyroid glands revealed mild follicular hyperplasia lined by cuboidal follicular cells with vacuolation in the colloid in group I. With higher doses (group II), there was more follicular hyperplasia lined by high cuboidal follicular cells and more vacuolation of the colloid in some follicles while many follicles showed depletion of the colloid. Also, there was significant increase in body weight in PCP treated groups compared to their control. This increase was dose and duration dependent and could be attributed physiologically to the reduction of T, and T, level in the serum. As T, and T, increase utilization of carbohydrates, increase protein catabolism and cause greater oxidation of fats, thus, elevate the basal metabolic rate and decrease the body weight.