Influence of cannabinoids on somatic cells in vivo.

Chromosomal and nuclear aberrations in bone marrow cells were studied in hybrid mice of genotype (C57BL x C3H)F1 following treatment with specific cannabinoids. In the subacute series, mice were treated for 5 consecutive days with delta 9-tetrahydrocannabinol (THC), cannabinol or cannabidiol at a dose of 10 mg/kg, the percentage of micronuclei in cannabinoid-treated mice was 3- to 5-fold greater than in the dimethyl sulfoxide controls. In the acute series, polychromatic erythrocytes were scored after a single exposure. In one acute series there was an approximately twofold increase in the incidence of micronuclei in the cannabinoid-treated mice; in the other acute series of cannabinoid-treated animals the micronuclei values were as high as 6 times the control values. Interaction between dose and frequency of exposure was assessed for THC; the number of micronuclei was affected by THC dosage, but not by frequency of exposure. Further confirmation of nuclear aberrations was obtained from assessment of bone marrow mitosis. In this limited study of mitotic cells the incidence of metaphase aberrations in cannabinoid-treated animals was 5-7 times greater than in controls.