POSTNATAL DEVELOPMENT OF THE THYROID GLAND IN OFFSPRING UNDER THE INFLUENCE OF PYRETHROID PESTICIDES DURING PREGNANCY

Abstract

Objective: To determine the structural and functional features of postnatal development of the thyroid gland in the offspring under conditions of intrauterine exposure to pyrethroid pesticides. Material and methods: The experiments were conducted on white sexually mature non pregnant female Wistar rats weighing 150-180 g, as well as on their offspring. Animals of the experimental groups received the pesticide fipronil (Vigor) at a dose of 3.6 mg/kg and the insecticide fastokin at a dose of 8 mg/kg daily until the end of the experiments. The material for the study, including thyroid gland samples, as well as blood serum of mothers and their offspring, were collected from the offspring of all groups of animals on the 3rd, 7th, 14th, 21st, and 30th days after birth. Results: Prenatal exposure to pyrethroid pesticides can alter the normal processes of postnatal ontogenesis of the thyroid gland in the offspring. The main structural and functional mechanisms of the negative impact of pyrethroids on the development of the thyroid gland during pregnancy have been identified. Conclusions: In the mechanism of development of thyroid dysfunction in offspring, an imbalance between the processes of proliferation and apoptosis of thyrocytes has been revealed, which leads to a weakening of the formation of thyroid follicles, as well as to submicroscopic changes indicating a violation of the secretory activity of thyrocytes.