ABSTRACT
The follicle cells of the thyroid gland maintain the body economy by regulating the synthesis, storage, and secretion of thyroid hormones necessary for growth, development, and normal body metabolism (39). The regulatory processes of the thyroid gland follicle cells appear to be readily altered by physiologic or chemi cal means (47). In fact, thyroid disorders are among the most frequently occur ring endocrine diseases seen by a physician (11,46). Fortunately, the more serious proliferative lesions of the follicle cells, including tumors, are more prevalent in the thyroid gland of the laboratory rat than that of the human (9,10,28,34,43,50).
