Evaluation of histophysiological function of thyroid in Liza abu from Musa creek

The hormones of pituitary-thyroid axis play an important role in the maintaining of the normal physiological status of the body in vertebrates. Therefore, disturbance in the function of this axis can affect other parts of the body. In the present study, 50 male and female Liza abu (with 45.51 ± 8.2 g body weight and 16.25 ± 0.88 cm body length) were collected from five stations in Musa creek including: 1) Petrochemical 2) Ghanam 3) Zangi 4) Doragh and 5) Patil stations. 10 L. abu were also caught at the Sajafi station (located in Musa creek) as a control site. Bleeding was carried out and the blood plasma was separated. Then, the plasma levels of thyroid hormones (triiodothyronine (T3) and tetraiodothyronine (T4)) were measured using ELISA method. Tissue samples were also taken from thyroid and were fixed in 15% formalin and prepared according to the routine histological process. The lowest and highest amounts of T3 and T4 hormones respectively, were measured in the fish plasma from Patil station. The most histopathological changes (such as hemorrhage) were observed in the fish from Petrochemical station. The results of this study indicated the adverse effects of environmental pollution on the balance of thyroid hormones.