Chronic exposure to multi-metals on testicular toxicity in rats

Despite the availability of sufficient data on the effects of individual metal exposure on living organisms, a critical knowledge gap still exists in predicting effects of multi-metals particularly on the pituitary-testicular axis. Thus, the aim of the present study was to check the effects of individual or combined (binary and ternary) exposure to aluminum, copper, and zinc on (i) sperm and testosterone levels (ii) oxidative stress and (iii) structural changes in testis of male Wistar rats. Animals were exposed to aluminum, copper, and zinc either individually (20 mg/kg, orally, once, daily), binary (10 mg/kg each, orally, once daily) or in ternary combination (5 mg/kg, each, orally, once daily) for 24 weeks. The exposure to aluminum, copper individually and in combination led to a significant decrease in sperm counts and an increased oxidative stress compared to the control group. Exposure to zinc caused significant decrease in oxidative stress and an increase in different sperm variables. The exposure to zinc with aluminum or copper had no toxic effects on testis while concomitant exposure to aluminum, copper, and zinc produced more pronounced testicular injury. In summary, while co-exposure to zinc with aluminum or copper produced reproductive toxicity the co-exposure to all the three metals may lead to a significant testicular toxicity and these changes were related to increase in oxidative stress in rats.

Automated summary

Exposure to aluminum, copper individually or in combination led to decreased sperm counts and increased oxidative stress, while exposure to zinc reduced oxidative stress and increased different sperm variables. Co-exposure to zinc with aluminum or copper resulted in reproductive toxicity, while simultaneous exposure to aluminum, copper, and zinc caused significant testicular injury and higher levels of oxidative stress in rats.