Environmental interaction of lead and cadmium on reproduction and metabolism of male rats.

To study the environmental interaction of lead and cadmium on reproduction and metabolism 70 male sprague Dawley rats were divided equally into 7 goups. Goups 1 and 2 served as controls, 3 and 4 were injected daily with 50 and 250 ug of lead respectively, 5 and 6 with 50 and 250 ug of cadmium respectively and group 7 with 25 ug of both lead and cadmium. After 70 days of injections rats were sacrificed. In group 6 cadmium injection caused enlargement of adrenal, liver, kidney and spleen but retarded growth, reduction in size of prostate, testes, epididymis and hepatic enzyme activity. Groups 4 and6 had the highest and most significant mineral concentration in blood and liver. Testes histology of group 7 showed an absence of spermatogenesis in some seminiferous tubules indicating that low levels of lead and cadmium together have a more synergetic damaging effect on rat testes than higher levels of lead or cadmium alone. This study suggests that blood mineral levels should be used with other more sensitive clinical tests to assess the toxicity picture in humans.