Influence of 60-day administration of tartrazine and infliction of a defect in the tibia on the histological structure and morphometric parameters of the rat’s thyroid gland

Abstract

Aim: to study the histological structure and histomorphometric parameters of the thyroid gland in rats in the period after the completion of the 60-day administration of tartrazine and the creation of a through defect in the tibiae.Material and methods. One hundred and fifty white male rats were divided into five groups: groups T1 and T2 - 60 days of exposure to tartrazine at a dosage of 750 and 1500 mg/kg; group K+D – 60-day administration of saline solution and infliction of a defect in the tibiae; groups T1+D and T2+D – 60-day exposure to tartrazine at a dosage of 750 and 1500 mg/kg and causing a defect in the tibia. The histological structure and histomorphometric parameters of the thyroid gland were studied on days 3, 10, 15, 24 and 45.Results. In the T1+D and T2+D groups, mainly small follicles, lined with cuboidal shaped cells, and in some of them - a flat or columnar shaped cells were detected in the center of the gland from days 3 to 15. Many thyrocytes had a vacuolated cytoplasm and an intensely stained nucleus. The heterogeneous colloid partially filled or was practically absent in the follicles cavity, anemia of the capillaries between them was determined. Singly areas of the organ parenchyma with a significant accumulation of lymphocytes were detected. Histomorphometric study showed a decrease in the internal diameter of the follicles, lumen-epithelial index and nucleo-cytoplasmic ratio and the raise in the height of the follicular epithelium and the area of the cytoplasm of follicular cells.Conclusion. Sixty-day administration of tartrazine to rats and artificial traumatic bone injury leads, in comparison with the data of control groups, to a more pronounced change in the histological picture and morphometric data of the thyroid gland. The intensity and duration of changes are dosedependent: in the T1+D group, most of the qualitative and quantitative changes are smoothed out by 45 days, and in the T2+D group, many of them remain, and the body does not adapt to them.