Effect of the synthetic cannabinoid nabilone on spermatogenesis in mice.

Chronic treatment of mice with the synthetic cannabinoid nabilone (50 mg/kg, 3 times per week) reduced the number of pachytene spermatocytes. Nabilone did not affect other cell types in the testis or the sex organ weights. Nabilone tended to increase the number of abnormal spermatozoa, but this did not reach statistical significance. It is concluded that nabilone causes less testicular toxicity than the natural cannabinoids.