Chronic lead exposure induces ultrastructural alterations in the monkey testis

The purpose of this study was to establish the effects of lead on the non-human primate testis. Sixteen cynomolgus monkeys maintained in environmentally controlled conditions were administered 1500 micrograms lead acetate/kg bw/day in gelatin capsules. Monkeys were randomly assigned to the following groups: control (n = 3), which received 95% glycerol and 5% distilled water (vehicle) over their lifetime for 9 years; infancy group (n = 4), exposure limited to the first 400 days of life; post-infancy group (n = 5), dosed following 300 days of life to 9 years of age; lifetime group (n = 4), dosed for nine years. All the animals were treated with lead or vehicle for the entire duration of the experiment. The organs from animals in the control group consisted of seminiferous epithelium comprised of typical Sertoli cells containing nuclei with numerous infoldings and longitudinally-oriented profiles of endoplasmic reticulum, microtubules, mitochondria, and lipid droplets that were scarce. Spermatogenic cell types at different developmental stages were observed. Seminiferous epithelium from animals of the treated groups exhibited distortion in the general architecture of the epithelium such that a marked decrease in its height was revealed. In particular, Sertoli cells contained heightened number of lipid droplets and lysosomal elements, and the basal lamina was usually stratified. The magnitude of alterations in the seminiferous tubules was indistinguishable among the three treated groups. These findings support the conclusion that lead is a potent testicular toxin.