delta 9-Tetrahydrocannabinol: a potent inhibitor of episodic luteinizing hormone secretion.

To determine if delta 9-tetrahydrocannabinol (THC) dosages comparable to those obtainable from marihuana cigarettes suppress episodic luteinizing hormone (LH) secretion, THC was administered to ovariectomized rats in doses of 31.2 to 500 microgram/kg b.wt. THC in doses of 62.5 microgram/kg b.wt. or greater rapidly suppressed episodic LH release and reduced serum LH concentrations by 42 to 68%. The period of suppression ranged from less than 30 min to more than 1 hr and was dose-dependent. These results indicate that acute exposure to relatively low doses of THC significantly disrupts gonadotropic hormone secretion in the rat and raise the question of whether episodic LH secretion in humans might be suppressed subsequent to the use of marihuana.