diabetes mellitus, oxygen therapy, infertility, testicular morphology, immunohistochemistry.

Diabetes Mellitus (DM) is characterized as a metabolic and chronic disorder, related to problems in the production, secretion and/or use of insulin, which is the hormone responsible for regulating blood glucose. There are several complications evidenced in diabetic individuals, from neuropathies, heart diseases, retinopathies, among many others, including infertility. Male individuals living with DM present alterations in their reproductive system, such as disturbances in spermatogenesis, reductions in testosterone levels, increased apoptosis of spermatogonia and spermatocytes, reduction in the number and mobility of spermatozoa, and alterations in the distribution of Leydig cells. Among the techniques that can prevent or mitigate the various damages caused by DM in the individual, hyperbaric oxygen therapy (HTO) is considered one of the most promising. In this technique, 100% oxygen at pressures greater than sea level or an absolute atmosphere (ATA) plays an influencing role in oxidative metabolism, thus enabling the reduction mainly of edema and inflammatory processes, offering benefits related to maintenance and/or tissue repair as in the case of wound healing. This study aims to analyze the action of hyperbaric oxygen therapy in preventing testicular morphological changes in diabetic rats induced by streptozotocin. Twenty-eight male Wistar rats (Rattus norvegicus) (60 days old), weighing 220-280g were divided into four groups: C (normoglycemic animals), n= 7; C+OTH (normoglycemic animals submitted to HBOT), n= 7; DM (diabetic animals) n= 7; D+OTH (diabetic animals submitted to HBOT), n=7. DM was induced by streptozotocin (40 mg/kg intraperitoneally) and treatment with HBOT was carried out for six weeks, on continuous days. After treatment the animals were weighed and euthanized and had the testicles collected and weighed. In the collected testes, histological analysis of tissue integrity was performed on slides stained with Hematoxylin and Eosin, as well as morphometric analysis on slides stained with toluidine blue, and immunohistochemistry with immunostaining for testosterone receptors. The treatment was not able to reduce the glycemia of the animals nor did it positively influence the biometric parameters. As for the morphometric parameters, the treatment was not able to improve the testicular tissue, with no significant differences between the diabetic and D+OTH groups regarding epithelium height, seminiferous tubule diameter and lumen diameter. A possible deleterious effect of HBO was observed regarding the height of the seminiferous epithelium, as well as the diameter of the lumen. However, more studies are needed to better understand this phenomenon. It was not possible to observe an increase in the availability of testosterone receptors in the treated animals.