STRUCTURE AND METABOLISM OF THE SKIN IN IODINE DEFICIENCY COMBINED WITH GOITROGEN CONSUMPTION

Iodine deficiency, combined with the consumption of natural goitrogens, such as soy and peanuts, which inhibit thyroid peroxidase activity, disrupts thyroid hormone synthesis. The disruption, in turn, results in structural and metabolic imbalances within the body. These conditions frequently occur due to the combination of endemic factors and specific dietary habits. Skin manifestations are among the earliest indicators of thyroid imbalance. However, scientific evidence on the sequential development of morpho-functional skin changes in iodine deficiency combined with goitrogen consumption remains limited, particularly concerning age-related characteristics and skin types (thin or thick). Therefore, this study aimed to examine the structural and metabolic changes in the back and paw skin of experimental animals throughout the progressive development of iodine deficiency combined with goitrogen consumption in postnatal ontogenesis. The experiment was conducted on 50 white non-pedigree rats, including 25 sexually immature animals (3-5 months old) and 25 sexually mature animals (6-8 months old). Eleven animals from each age group constituted the control group (Group 1). In contrast, 14 animals from each age group were allocated to the experimental groups (Groups 2 and 3) and exposed to iodine deficiency combined with soy and peanut consumption. Tissue samples were collected on days 60 and 90 of the experiment. The research material included depilated skin from the back and metatarsal pads, their homogenates, and blood and urine samples. Morphological, morphometric, and biochemical analyses were conducted using statistical data processing. The study revealed alterations in the epidermal structure and keratinization processes. In the back skin of immature animals, the epidermal thickness on day 60 of the experiment was 3.1 % below the age norm (p˂0.001), and by day 90, it decreased to 5.5 % (p˂0.001). In mature animals, the epidermis was thinned by 1 % and 2.5 % (p˂0.01) on days 60 and 90, respectively. In the paw skin, the epidermis slightly thickened over the observation periods in mature animals, whereas in immature animals, it thinned by 6.5 % by day 90 (p˂0.001). In the edematous dermis, the volumetric density of collagen and elastic fibers changed according to changes in hydroxyproline and elastase content. Thus, the induced condition, validated by a significant reduction in urinary iodine concentration, disrupted thyroid homeostasis, resulting in morpho-functional changes in both thin and thick skin across all experimental animal groups.