Effects of cannabinoids given orally and reduced appetite on the male rat reproductive system.

Chronic oral treatment of young adult male Fischer rats with delta 9-tetrahydrocannabinol (THC), 1, 5 and 25 mg/kg/day, or crude marihuana extract (CME), 3, 15 and 75 mg/kg/day, suppresses growth of accessory sex organs and body weight gain in a dose-related manner. Animals pair fed with the THC (25 mg/kg) group gained slightly more in body weight than the THC group, but their relative accessory sex organ weights were intermediate between THC and ad libitum-fed control group weights. These latter differences may be due to altered serum androgen levels since these levels 2-6 h after last treatment were 0.15, 0.77 and 3.33 ng/ml for THC, pair-fed and ad libitum-fed groups, respectively. 24 h after the last treatment all groups were within normal levels. Thus, chronic cannabinoid treatment suppresses accessory sex organ weights and serum androgen levels greater than the suppression caused by reduced food intake alone.