Quantitative evaluation of spermatogenesis in mice following chronic exposure to cannabinoids

In mice, chronic administration of crude marihuana extract (CME), delta-9-tetrahydrocannabinol (THC), cannabidiol (CBD) and cannabinol (CBN) (50 mg kg-1 body weight for 15 and 35 days) impaired spermatogenesis at both mitotic and meiotic stages. Although the total number of step 7 spermatids was unaltered, mature spermatozoa recovered from the cauda epididymidis showed severe abnormalities in morphology. Body weight and sex organ weights were not affected markedly but the adrenal gland was hypertrophied. Leydig cell nuclear area was increased by CME and CBD and reduced by CBN. Cannabis deranges several stages of the spermatogenic cycle, most of the activity of the crude extract being attributable to CBN and CBD.