Protective effects of L-arginine against aluminum chloride-induced testicular damage in rats

Aluminum (Al) is a toxic metal that is frequently be exposed because it is found in many products used in daily life and in nature. L-arginine is one of the semi-essential amino acids, it is involved in many biochemical pathways in the body and has antioxidant effects. İn this study, it was aimed to investigate the possible protective effects of L-arginine on testicular toxicity caused by AlCl3. In this study, 28 male Wistar Albino rats, 8 weeks old, were used. At the beginning of the experiment, the weights of the rats were measured and randomly divided into 4 groups (n =7): Control, Al, Al+L-arginine, L-arginine. During the experiment, no application was applied to the rats in the control group. 20 mg / kg / day AlCl3 were administered the rats in Al group. 20 mg / kg / day AlCl3 and 50 mg / kg / day L-arginine were administered the rats in Al+L-arginine group. 20 mg / kg / day L-arginine were administered the rats in L-arginine group. AlCl3 and L-arginine were dissolved in saline and applications were carried out intraperitoneally (i.p.) for 4 weeks. At the end of the experiment, all rats were decapitated. Blood samples were taken to determine testosterone levels. Epididymis tissues were taken for spermiogram test and testicular tissues were taken for histopathological evaluations. Testicular tissue was passed through routine histological series and embedded in paraffin blocks. While some of the sections were stained by histochemical methods, some by TUNEL method, the immunoreactivity of 4-Hydroxynonenal (4-HNE) and 8-Hydroxy-2'-Deoxyguanosine (8-OHdG) was evaluated with some of them. Al treatment significantly decreased the percentage of body weight variation and testosterone concentration of the rats, however, improvement in these values was observed in the group treated with Al and L-arginine. It was determined that Al reduces sperm motility and concentration and also increases the abnormal sperm rate. L-arginine applied with Al has positive effects on all three parameters, especially sperm concentration. In light microscopic examination, it was determined that the testicular tissues of the control group were in natural appearance. In the testicular tissues of the Al group, vacuolar degeneration and atrophy in germinal epithelium, immature cells belonging to the spermatogenic series in the lumen of the seminiferous tubule, edema congestion in the interstitial area and focal hyperplasia in Leydig cells were observed. It was determined that these findings decreased significantly in the Al + L-arginine group. Testicular cross-sections of the L-arginine group were also observed in natural appearance, like the control group. The apoptotic index, 4-HNE and 8-OHdG immune reactivity of the Al group were significantly higher than all groups, and L-arginine was found to have positive effects on these findings. As a result, in this study, it was determined that Al damages the male reproductive system by increasing oxidative stress, and thanks to the antioxidant properties of L-arginine, which is used for protection against Al exposure, it has been determined that the negative effects of Al are significantly reduced. Keywords: Aluminum, L-arginine, TUNEL, 8-OHdG, 4-HNE, Histochemistry, Testis