Effects of the oral administration of Cannabis sativa (dagga) on chacma baboons (Papio ursinus).

Eighteen adult chacma baboons were fed Cannabis sativa, the plant material being incorporated into their food. They were divided into three equal groups. Group 1 animals were fed on 2% cannabis in food for 4 months, after which 2 animals remained on 2%, 2 were given 4% and 2 6% cannabis in food for the next 4 months. They became mildy apathetic. Five gained weight. Serum glucose, potassium and CO2 values decreased. Neuropathological examination of their brains did not show any significant abnormality. Group 2 animals were fed 10% cannabis for several weeks. They ate less and lost weight, and later became very apathetic. Right temporal biopsies were done in all and in 3 the tissue was analysed for glutamine, glutamate, tryptophan, ammonia and cyclic AMP. No significant change was found. Serum glucose and CO2 levels rose and potassium levels fell. Blood cholesterol values decreased in 3 of the 9 males. Group 3 animals were fed 6% cannabis for 2--4 months. Radio-immunoassay of sera and urine showed the presence of cannabinoids. They became apathetic, and 5 lost weight. Serum glucose and potassium levels (measured in the males) decreased. No neuropathological lesions were found in the brains, apart from an incidental leptomeningitis in 1 animal which died suddenly. The question of cannabis encephalopathy is discussed.