The ring test: a quantitative method for assessing the 'cataleptic' effect of cannabis in mice.
1. A bioassay for cannabis, called the ring test, has been developed in which the percentage of the total time spent on a horizontal wire ring during which a mouse remains completely immobile is recorded.2. The effect of cannabis on mobility is a dose-related, graded response.3. Threshold doses of cannabis extract are 12.5 mg/kg when injected intravenously, and 100 mg/kg when injected intraperitoneally or subcutaneously.4. The method provides a measure of the ;cataleptic' effect of cannabis. Chlorpromazine in doses of 1 mg/kg upwards also produces the effect but barbitone does not.5. It is concluded that Delta(1)-tetrahydrocannabinol (Delta(1)-THC) is largely responsible for the effect of cannabis extract on mobility; the potency ratio of Delta(1)-THC to cannabis extract is between 10 and 20. Delta(1)-Tetrahydrocannabidivarol (Delta(1)-THD) also affects mobility but is less active than Delta(1)-THC. Cannabidiol has no effect when injected intraperitoneally in doses up to 100 mg/kg.
D000818:Animals; D001463:Barbiturates / Q000494:pharmacology; D001522:Behavior, Animal / Q000187:drug effects*; D001681:Biological Assay; D002188:Cannabis / Q000008:administration & dosage / Q000494:pharmacology*; D002746:Chlorpromazine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D008722:Methods; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D008517:Phytotherapy; D011187:Posture; D013997:Time Factors
D001463:Barbiturates; D002746:Chlorpromazine