Cadmium affects testes and semen of rabbits exposed before and after puberty

Semen quality and testicular characteristics were measured in 92 rabbits in three controlled experiments with males exposed to cadmium chloride (Cd) when 12 or 27 weeks old. Doses of Cd were administered subcutaneously (s.c.), orally, or intravenously (i.v.) and subsets of animals were unilaterally castrated or not to evaluate the testes and to collect semen repeatedly from males when adults. There was considerable variability but Cd given at 12 weeks of age in doses of 0.08 mmol/kg s.c., 0.20 mmol/kg orally, and 0.02 mmol/kg i.v. tended to depress sperm output of these males when adults. The 0.02 mmol/kg dose given i.v., 0.4 mmol/kg orally, and 0.16 mmol/kg s.c. were lethal to many animals. Treatment of adults resulted in a generally similar pattern of systemic toxicity, and limited comparisons suggested that testicular sensitivity was slightly less than for young males. Androgenic function usually was maintained, as indicated by normal libido and seminal volumes even in males with reduced spermatogenesis. Necropsies confirmed previous findings of hyperemia, hemorrhaging, necrosis, and destruction of all spermatogenic elements in severely affected males.