Evaluation of the Reversibility of Cadmium-Induced Testicular Toxicity Following Recovery Alone or with Zinc Supplementation

Abstract

Cadmium (Cd) is a toxic heavy metal that disrupts spermatogenesis and steroidogenesis due to its long half-life. This study evaluated the impact of recovery alone or with zinc (Zn) supplementation on Cd-induced testicular toxicity. A total of 42 pubertal male Wistar rats were divided into seven groups of six rats each. The control group (1) received NaCl (0.9%). Groups 2, 3, and 4 were treated with Cd 10 μg/kg/d by intraperitoneal injection for 1, 2, and 3 months respectively. Group 5 received Cd for 3 months with a recovery period of 1 month; Group 6 was exposed to Cd for 3 months, followed by a 1-month recovery period combined with Zn supplementation. (0.5 mg/kg/d). The last group was treated with zinc at a dose of 0.5 mg/kg/day for one month. The results showed decreased body weight, testicular and epididymal weight, testicular dimensions, and sperm parameters, along with Cd accumulation in the testes. Cd caused testicular damage and reduced serum testosterone levels, with more pronounced effects in the 3-month treatment group. Recovery alone did not significantly reverse Cd's toxic effects, whereas Zn supplementation mitigated most of the damage. Recovery combined with Zn supplementation was more effective in correcting Cd-induced testicular toxicity than recovery alone.

Keywords: cadmium; recovery; testicular toxicity; zinc.

Figure 1

Histological sections of the testes of the control (a) and Cd rats treated for one month (b), two months (c), and three months (d). IT: interstitial tissue, SP: spermatozoa.

Figure 2

Impact of recovery alone or with zinc supplementation on sperm parameters after Cd for 3 months of Cd treatment. Sperm count (a); sperm motility (b); sperm viability (c); normal morphology (d); means ± SD of six animals in each group, statistically significant differences are indicated as follows: ^a vs. control, ^b vs. Cd3, * p < 0.05, ** p < 0.01.

Figure 3

Influence on recovery alone or in combination with Zn on plasma testosterone levels in the group treated with Cd for 3 months. Means ± SD of six animals in each group, statistically significant differences are indicated as follows: ^a vs. control, ** p < 0.01.

Figure 4

Concentration of Cd (a) and Zn (b) in the testes of rats. Means ± SD of six animals in each group, statistically significant differences are indicated as follows: ^a vs. control, ^b vs. Cd3, * p < 0.05, ** p < 0.01, ND: non-detectable.

Figure 5

Histological sections of the testes from control rats: (a) rats treated with Zn alone (b) treated with Cd for three months (c) rats that recovered for 1 month, (d) rats that recovered for 1 month with Zn supplementation, and (e) abbreviations on the image: IT: interstitial tissue, SP: spermatozoa.