Combined effects of arsenic exposure and diabetes on male reproductive functions

Abstract

Background: It is known that exposure to either arsenic or hyperglycemia can induce male reproductive damages. However, their combined effects on male reproductive organs are still unclear. Therefore, the present study investigated morphological and functional parameters of the testis, epididymis, and spermatozoa in diabetic rats exposed to arsenate. Materials and methods: Diabetes was induced in male rats by intraperitoneal streptozotocin injection. While a set of healthy and diabetic animals received saline solution (negative control and diabetes control, respectively), the other set received 10 mg/L sodium arsenate (arsenic control and diabetes + arsenic groups, respectively) for 40 days in drinking water. Testosterone concentration, daily sperm production, sperm counts in the testis and epididymis, and sperm parameters were evaluated in the groups. Moreover, testis and epididymis were subjected to antioxidant enzymes analysis, micromineral determination, and histopathological evaluation. Results: Arsenate exposure reduced serum testosterone concentration in healthy animals and worsened this reduction in diabetic rats. In addition, the number of spermatozoa in testis and epididymis tissues, as well as the daily sperm production, was decreased in these groups. Sperm parameters such as motility, morphology, and integrity of acrosomal and plasma membranes were impaired in health animals exposed to arsenate. The combination of diabetes and arsenate, in turn, increased only the percentage of spermatozoa with abnormal morphology. Moreover, the proportion of arsenic increased in the testis and epididymis of both groups receiving arsenate. Its bioaccumulation in these organs caused an imbalance in antioxidant enzymes activities and mineral content in healthy animals, enhancing these changes in diabetic rats. Testicular pathologies occurred mainly in animals co-exposed to diabetes and arsenate. Conclusion: Our results indicate that arsenate exposure enhances several damages to male reproductive functions in diabetic rats, mainly by impairing testosterone levels and inducing nitrosative stress in testis and epididymis.

Green Tea Infusion Ameliorates Histological Damages in Testis and Epididymis of Diabetic Rats

“…Notably, testis and epididymis are well known as androgen-dependent organs (Mäkelä et al, 2019). Moreover, in STZ-induced diabetic animals, studies indicated that low testosterone level is a relevant factor acting on the morphometrical alterations observed here, such as reduction in the tubular diameter, the epithelial height, and the number of Sertoli and germ cells that, in the end, influenced the diminished DSP (Kianifard et al, 2012; Korejo et al, 2016; Das et al, 2017; Corrêa et al, 2019; Souza et al, 2019). Altogether, these results confirmed the adverse effects of diabetes on the testis and epididymis of Wistar rats.…”

“…The decreased proportion of Se in the testis may also contribute to this result by altering the activity of glutathione-related enzymes (Rotruck et al, 1973). While it is well characterized that diabetes disturbs the adaptative mechanism of the testis to act against the ROS (Souza et al, 2019), the antioxidant role of green tea is still controversial. Das et al (2017) reported an increase in the activity of SOD and CAT in the testis of hyperglycemic rats treated with green tea, whereas Roychoudhury et al (2017) described the pro-oxidant activity of green tea catechins in reproductive organs.…”

“…In the epididymis, the treatment with green tea was able to mitigate most of the morphometrical changes caused by diabetes. Morphometrical alterations are usually associated with sperm production and testosterone levels (Robaire & Viger, 1995; Hermo & Robaire, 2002; Souza et al, 2019). Despite the low testosterone, the improved DSP by green tea intake influenced the recovery of epididymal parameters, such as luminal diameter, epithelium height, and the percentage of the lumen with sperm in the epididymal regions.…”

“…The normality was analyzed using the Shapiro–Wilk test. Subsequently, the results were submitted to two separate Student's t -test according to previous studies (Souza et al, 2019; Ladeira et al, 2021). The first analysis evaluated the effectiveness of type 1 diabetes induction comparing healthy animals (negative controls) with STZ-induced diabetic animals (diabetes control).…”

“…Indeed, diabetes induces reproductive disorders, such as alteration in the hypothalamus–pituitary–gonadal axis, reduction in serum testosterone levels, dysregulation of antioxidant enzymes with the generation of reactive oxygen species (ROS), and damage to testis and epididymis tissues (Murray et al, 1985; Sexton & Jarow, 1997; Bal et al, 2011; Martins et al, 2014). Likewise, experimental studies have shown that streptozotocin (STZ)-induced diabetes results in DNA damage and decreased sperm count in the testis, accompanied by a decrease in epididymal sperm motility (Shrilatha & Muralidhara, 2007; Navarro-Casado et al, 2010; Souza et al, 2019).…”