Banca de DEFESA: JOSE ANDERSON DA SILVA GOMES

EFFECT OF EXOGENOUS MELATONIN ON THE TESTICLES OF WISTAR RATS SUBJECTED TO EARLY WEANNING

Malnutrition. Melatonin. Spermatogenesis. Reproduction. Breastfeeding.

Proper nutrition during the critical period of development has a profound impact on the maturation of the reproductive structures and functions of mammals. Changes in this pattern can lead to nutritional imbalance. Among all affected systems, the reproductive system can be acutely and chronically affected, potentially leading to fertility problems. In this context, melatonin serves as an adjunct to nutritional therapy in the treatment and reversal of complications arising from malnutrition. Therefore, the present study aimed to investigate the activity of melatonin as a tool in reversing testicular damage. For this purpose, Wistar rats were used, which were divided into 4 experimental groups: control group; early weaning group; early weaning group treated with melatonin applied at a dose of 200μg per 100g of the animal's weight; early weaning group treated with the vehicle, composed of ethanol and saline solution. Except for the control group, all others were weaned on the 16th day after birth. Body weight was measured weekly, and euthanasia was performed when the animals reached 51 days of age. The testicles were weighed and collected for histopathological, morphometric, immunohistochemical, and statistical analysis. At the end of the study, it was possible to identify an increase in body mass in the early weaning group, as well as structural alterations, where this group showed a reduction in the diameter and height of the seminiferous tubule epithelium, as well as atrophy, vacuolization, and degeneration of germ cells. Another observation is that the early weaning group also exhibited reduced production of pachytene spermatocytes and Sertoli cells. In contrast, the group treated with melatonin showed improvement in all these analyzed parameters when compared to the control and early weaning groups. The results of immunohistochemistry also demonstrate that the melatonin-treated group had PCNA receptor labeling similar to the control group, indicating greater cell proliferation in this tissue, which was not observed in the other early weaning groups, including those treated with the vehicle. This demonstrates the restorative role of melatonin in testicular tissue.