Brain cannabinoid systems as targets for the therapy of neurological disorders.

Unprecedented developments in cannabinoid research within the past decade include discovery of a brain (CB1) and peripheral (CB2) receptor; endogenous ligands, anandamide, and 2-arachidonylglycerol; cannabinoid drug-induced partial and inverse agonism at CB1 receptors, antagonism of NMDA receptors and glutamate, and antioxidant activity; and preferential CB1 receptor localization in areas subserving spasticity, pain, abnormal involuntary movements, seizures, and amnesia. These endogenous structures and chemicals and mechanisms are potentially new pathophysiologic substrates, and targets for novel cannabinoid treatments, of several neurological disorders.

AM630 is an inverse agonist at the human cannabinoid CB1 receptor.

The present investigation examines WIN 55,212-2 and AM630 at the cloned human cannabinoid CB1 receptor stably expressed in Chinese hamster ovary (CHO) cells. The effect of various concentrations of WIN 55,212-2 and AM630 on basal [35S]GTPgammaS binding to cell membranes was determined. WIN 55,212-2 (100 microM) stimulated basal [35S]GTPgammaS binding 77.

Relative efficacies of cannabinoid CB1 receptor agonists in the mouse brain.

We measured (-)-5-(1,1-dimethylheptyl)-2-[5-hydroxy-2-(3-hydroxypropyl)cyclohe xyl]-phenol (CP 55,940)-, (-)11-OH-delta8-tetrahydrocannabinol-dimethylheptyl (HU-210)-, anandamide- and delta9-tetrahydrocannabinol-stimulated G protein activation in mouse brain using the [35S]GTPgammaS functional assay. The Ki values for these drugs were determined by agonist competition binding with the cannabinoid CB1 receptor antagonist [3H]N-(piperidin-1-yl-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4- methyl-1H-pyrazole-3-carboxamidehydrochloride ([3H]SR141716A). This information was used to calculate the efficacy for drug stimulation of G protein activity.

SR141716A is an inverse agonist at the human cannabinoid CB1 receptor.

The effects of R(+)-[2,3-dihydro-5-methyl-3-[(morpholinyl)methyl]pyrrolo[1,2,3-de]-1,4- benzoxazin-yl]-(1-napthalenyl)methanone mesylate (WIN 55,212-2) and N-piperidino-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-3-pyrazo le-carboxamide (SR141716A) on guanosine-5'-O-(3-[35S]thio)triphosphate ([35S]GTPgammaS) binding to membranes isolated from human cannabinoid CB1 receptor-transfected Chinese hamster ovary (CHO) cells were examined. WIN 55,212-2 stimulated [35S]GTPgammaS binding 76.3% above basal levels whereas SR141716A produced a 22.

delta 9-Tetrahydrocannabinol is a partial agonist of cannabinoid receptors in mouse brain.

We measured the ability of the cannabinoid agonists delta 9-tetrahydrocannabinol and R(+)-[2,3,-dihydro-5-methyl-3- [(morpholinyl)methyl]pyrrolo[1,2,3-de]-1,4-benzoxazin-yl]-(1-napht halenyl) methanone mesylate (WIN 55,212-2) to stimulate guanosine-5'-O-(3-[35S]thio)triphosphate ([35S]GTP gamma S) binding in mouse brain membranes. delta 9-Tetrahydrocannabinol stimulated [35S]GTP gamma S binding by about 25% as compared to WIN 55,212-2. This is the first report demonstrating that delta 9-tetrahydrocannabinol acts as a partial agonist in stimulating [35S]GTP gamma S binding in the mouse brain.

AM630 antagonism of cannabinoid-stimulated [35S]GTP gamma S binding in the mouse brain.

This research was designed to determine the action of the novel aminoalkylindole AM630 (6-iodo-pravadoline) at the cannabinoid receptor by studying its interaction with the cannabinoid receptor agonist WIN 55,212-2 (R(+)-[2,3-dihydro-5-methyl-3-[(morpholinyl)methyl]pyrrolo [1,2,3-de]-1,4-benzoxazin-y]-(1-naphthalenyl)methanone mesylate) on guanosine-5'-O-(3-[35S]thio) triphosphate ([35S]GTP gamma S) binding in mouse brain. WIN 55,212-2 stimulated [35S]GTP gamma S binding, while AM630 had no effect. AM630 antagonized WIN 55,212-2-2induced [35S]GTP gamma S binding and shifted the WIN 55,212-dose-response curve to the right.

AM630 is a competitive cannabinoid receptor antagonist in the guinea pig brain.

AM630 has been demonstrated to be a cannabinoid receptor antagonist in the mouse brain and vas deferens. Conversely, it was recently reported that AM630 acts as a cannabinoid agonist in the guinea pig ileum. This research was designed to determine whether the difference in the action of AM630 is species specific.

The perceived effects of smoked cannabis on patients with multiple sclerosis.

Fifty-three UK and 59 USA people with multiple sclerosis (MS) answered anonymously the first questionnaire on cannabis use and MS. From 97 to 30% of the subjects reported cannabis improved (in descending rank order): spasticity, chronic pain of extremities, acute paroxysmal phenomenon, tremor, emotional dysfunction, anorexia/weight loss, fatigue states, double vision, sexual dysfunction, bowel and bladder dysfunctions, vision dimness, dysfunctions of walking and balance, and memory loss. The MS subjects surveyed have specific therapeutic reasons for smoking cannabis.

Antisense oligodeoxynucleotide treatment to the brain cannabinoid receptor inhibits antinociception.

Studies using agonists from at least three major cannabinoid ligand groups suggest the mediation of several distinct effects (e.g. psychotropic, analgesia, and antiemetic) by the recently cloned CB1 cannabinoid receptor.

Comparison of a new ovine antigen binding fragment (Fab) antivenin for United States Crotalidae with the commercial antivenin for protection against venom-induced lethality in mice.

Snake venom poisoning is a medical emergency requiring immediate attention and the exercise of considerable judgment. Of the estimated 8,000 bites inflicted by venomous snakes in the United States each year, approximately 6,000 are treated with commercial antivenin. The only commercially available antivenin for North American Crotalidae envenomation is Antivenin (Crotalidae) Polyvalent (equine origin) (ACP; Wyeth Laboratories, Philadelphia, PA).

Controlled clinical trial of cannabidiol in Huntington's disease.

Based on encouraging preliminary findings, cannabidiol (CBD), a major nonpsychotropic constituent of Cannabis, was evaluated for symptomatic efficacy and safety in 15 neuroleptic-free patients with Huntington's Disease (HD). The effects of oral CBD (10 mg/kg/day for 6 weeks) and placebo (sesame oil for 6 weeks) were ascertained weekly under a double-blind, randomized cross-over design. A comparison of the effects of CBD and placebo on chorea severity and other therapeutic outcome variables, and on a Cannabis side effect inventory, clinical lab tests and other safety outcome variables, indicated no significant (p greater than 0.

Assay of plasma cannabidiol by capillary gas chromatography/ion trap mass spectroscopy following high-dose repeated daily oral administration in humans.

Plasma levels of cannabidiol (CBD) were ascertained weekly in 14 Huntington's disease patients undergoing a double-blind, placebo-controlled, crossover trial of oral CBD (10 mg/kg/day = about 700 mg/day) for 6 weeks. The assay procedure involved trimethylsilyl (TMS) derivatization of CBD and the internal standard delta-6-tetrahydrocannabinol (THC), capillary column gas chromatography, ion trap mass spectroscopy in positive ion chemical ionization mode using isobutane, and calculations of CBD levels based on peak ion intensity of the 387 M + H peak of delta-6-THC-TMS and the 459 M + H peak of CBD-2TMS. The sensitivity of the assay was about 500 pg/ml, and the precision was about 10-15%.

Enantiomeric cannabinoids: stereospecificity of psychotropic activity.

The 1,1-dimethylheptyl homolog of (-)-(3R,4R)-7-hydroxy-delta-6- tetrahydrocannabinol (compound II) is highly psychotropic in mice, rats and pigeons. The (+)-(3S,4S) enantiomer (III) was found to be psychotropically inactive at doses up to several thousand times those of the ED50 of (II).

Intraspinal opiates for treatment of intractable pain in the terminally ill cancer patient.

The discovery of opiate receptors and then their endogenous ligands in 1974 (Snyder et al., 1974) has elucidated a vast pharmacology of opiates providing a basis for their diverse clinical applications. With the awareness of quality of life as a primary goal in terminal cancer patients, widespread attention has been drawn to the direct delivery of long-term intraspinal analgesics to cancer patients for who all medical pain control regimens have failed (Coombs & Saunders, 1974).

Structure-anticonvulsant activity relationships of cannabidiol analogs.

Cannabidiol (CBD) exhibits anticonvulsant activity in experimental animals and in man. As part of a structure-activity study, analogs were prepared wherein the terpene unit, the aryl unit, and/or the side chain were modified. Thus, several pinenyl and carenyl derivatives, aryl ethers and acetates, and a variety of 1",1"-dialkylhexyl and 1",1"-dialkylheptyl analogs were synthesized.

Stereochemical requirements for cannabimimetic activity.

The SAR of cannabimimetic activity in the cannabinoid series are reviewed with emphasis on the stereochemical requirements. Some new results are presented. The most important are that a, in humans, (-)-(1S)-delta-3-THC is much more active than (+)-(1R)-delta-3-THC; and b, with the 7-OH-delta-6-THC DMH enantiomers (32) and (33), the activity in several animal species resides completely in the (-)-(3R, 4R) enantiomer (32), the difference between the two enantiomers being up to several thousand times.

Anticonvulsant and neurotoxic effects of tetrahydrocannabinol stereoisomers.

Enantiomers of delta-6-tetrahydrocannabinol (THC), delta-6-THC-1'', 1''-dimethylheptyl (DMHP), and 7-OH-delta-6-THC-1'',1''-DMHP were assessed for their ability to block audiogenic seizures in genetically epilepsy-prone rats. The stereoisomers were evaluated also for their ability to produce differential neurotoxicity in the rat rotorod (ROT) paradigm. Potency comparisons among the compounds revealed modest to profound stereoselectivity for anticonvulsant and neurotoxic activities, a general increase in both activities with the DMHP and 7-OH modifications of delta-6-THC, and some favorable separation between anticonvulsant and neurotoxic activities with selected THC analogs.

Open label evaluation of cannabidiol in dystonic movement disorders.

Cannabidiol (CBD), a nonpsychoactive cannabinoid of Cannabis, was given to 5 patients with dystonic movement disorders in a preliminary open pilot study. Oral doses of CBD rising from 100 to 600 mg/day over a 6 week period were administered along with standard medication. Dose-related improvement in dystonia was observed in all patients and ranged from 20 to 50%.

Stock differences in the susceptibility of rats to learned helplessness training.

Learned helplessness (LH) consists of shock escape deficits evidenced by animals previously exposed to inescapable shock. This phenomenon has shown promise as a behavioral screen for new antidepressant drugs. Unfortunately, some stocks of rats evidence low susceptibility to LH training.