Effect of tetrahydrocannabinol on the hypothalamic-pituitary axis in the ovariectomized rhesus monkey

Single doses of delta9-tetrahydrocannabinol (THC) (5.0, 2.5, 1.25, or 0.625 mg/kg) can decrease the levels of both luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in the ovariectomized rhesus monkey. The inhibition of gonadotropins (50% to 88%) lasts for 6 to 24 hours depending upon the dose of THC. There are no great differences in the responses of the two gonadotropins to THC. The inhibition of gonadotropin levels by THC appears to be at the level of the hypothalamus, since both LH and FSH are released from the pituitary gland in response to LH- releasing factor in the presence of THC.