Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Administration of delta 9-tetrahydrocannabinol (THC; 0.75-4.0 mg/kg IP) to rhesus monkeys produced a biphasic pattern of high-voltage slow waves (HVSW) and fast waves (HVFW) EEG, along with behavioral depression and alertness, respectively. The HVSW phase appeared 20 to 30 min after drug injection and was uniquely characterized by spike-bursts in frontal and temporal lobes and hypothalamus, theta-waves in parietal and occipital lobes, and generalized HVSW in subcortical regions. During the HVSW phase, bradycardia and hypothermia occurred, and animals exhibited depression or sedation. After the HVSW phase lasting for 3-4 hr, HVFW predominated in overall EEGs with marked decrease in neocortical spike-bursts. Bradycardia and hypothermia occurred simultaneously 20 to 30 min after drug injection and reached maximal levels (30-40 percent decrease in heart rate, 1.5-2.0 degrees C decrease in body temperature) 2 to 3 hr after injection. The dose- and time-response relationships for bradycardia and hypothermia paralleled the HVSW phase with behavioral depression. Animals were alert and calm during recovery from bradycardia and hypothermia. THC levels and disposition in blood correlated with bradycardia, hypothermia and EEGs and behavioral changes following THC administration.
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PMID:delta 9-Tetrahydrocannabinol: EEG changes, bradycardia and hypothermia in the rhesus monkey. 282 7

The many studies that have been included in this review suggest that cannabinoids have ubiquitous effects on biological systems. These results also underscore the intensity to which cannabinoids have been studied. While there are numerous reasons for the prodigious amount of cannabinoid research, a major stimulus has been the desire to identify a specific biochemical event or pathway that is responsible for the expression of delta 9-THC's unique psychoactivity. It is the hope that delta 9-THC, as with all centrally acting drugs, might serve as an important tool for achieving a better understanding of the central nervous system. As discussed in this review, the psychoactivity of cannabinoids might best be described as a composite of numerous effects. If that is indeed the case, then it would seem logical that these centrally mediated effects do not arise from a single biochemical alteration, but rather from multiple actions. Of course, a major problem arises when one attempts to establish a relationship between cause and effect when multiple mechanisms and effects are involved. An initial approach to reducing the complexity of elucidation of mechanism of action should involve attempts to distinguish those cannabinoid actions which result in specific effects (psychoactivity) from those which produce non-psychoactive effects (such as general depression). There are several fundamental principles that can be used to assess specificity, including concentration or dose of the drug that is required to produce a given effect. Low doses of delta 9-THC are capable of producing the psychoactivity that is unique to cannabinoids, whereas higher doses may produce effects that are both specific and nonspecific for cannabinoids. Unfortunately, establishing this basic tenet for delta 9-THC has proven to be difficult. It has not been possible to establish the concentration of delta 9-THC at its site of action that is necessary to produce a given pharmacological effect. While it is a simple matter to measure the concentration of cannabinoids in either a whole tissue or an incubation medium, the hydrophobicity of cannabinoids dramatically affects their affinity for, and hence concentration in, the biochemical components of the tissue. If the concentration of delta 9-THC could be measured at its site of action, then the relevance of many of its pharmacological effects could be adequately determined. Two possible mechanisms by which cannabinoids might produce psychoactivity are membrane perturbation and receptor interactions, and indeed, both mechanisms have received considerable attention.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Cellular effects of cannabinoids. 287 89

In vitro intracellular recording techniques were used on an excitatory neuromuscular junction of a walking-limb stretcher muscle of the lobster in order to define the synaptic pharmacology of delta-9-tetrahydrocannabinol (THC), 11-hydroxy-THC and cannabidiol. Delta-9-tetrahydrocannabinol and 11-hydroxy-THC, in relatively small concentrations, increased the amplitude of the excitatory junctional potential and the mean quantum content of a muscle fiber, whereas larger concentrations produced depression. In contrast, cannabidiol reduced the excitatory junctional potential and the mean quantum content. All three cannabinoids, however, depressed the amplitude of the spontaneous miniature junctional potential. The changes in mean quantum content point to a presynaptic site of action for the drug, while the reduction of the amplitude of the miniature junctional potential presumes a postsynaptic site. Such findings suggest synaptic mechanisms and sites of action for the central excitatory and depressant properties of the cannabinoids.
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PMID:Changes in neurotransmitter release at a neuromuscular junction of the lobster caused by cannabinoids. 290 83

The antinociceptive activity of delta 9-THC was found to be 45 times greater after i.v. (ED50 = 1.0 mg/kg) than after s.c. administration while its ability to depress spontaneous activity was increased only 8 fold. Route of administration had less of an impact on the antinociceptive potency of hydroxylated metabolites and analogs of delta 9-THC. The structural requirements for antinociception and depression of spontaneous activity were found to be similar. Both routes of administration and structural alterations dramatically changed the antinociceptive potency of delta 9-THC.
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PMID:Structural requirements for cannabinoid-induced antinociceptive activity in mice. 298 3

Several C-10 substituted cannabidiol (CBD) derivatives and novel oxepin derivatives of delta 9-tetrahydrocannabinol (delta 9-THC) were synthesized and evaluated for biological activity in mice and dogs. Treatment of 10-bromocannabidiol diacetate (3) with various amines in Me2SO gave the corresponding 10-aminocannabidiol derivatives 4-6. Similarly, treatment of 3 with NaN3 gave the azido compound 7, which with LiA1H4 afforded the 10-aminocannabidiol 9. However, reduction of 7 with CrCl2 formed the amide 8, which on further reduction with LiA1H4 gave the N-ethyl analogue 10. Coupling of 9 with 11 in the presence of dicyclohexylcarbodiimide formed 12, which was then deprotected with HCl to give the analogue 13. The oxepin analogue 14a was synthesized from 3 by treatment with Na2CO3 in CH3OH/H2O at room temperature. The dimethylheptyl analogue 14b was similarly prepared. Incorporation of N-ethyl (10), N-methyl-N-propargyl (6), and morpholino (4) groups in CBD at position 10 resulted in analogues that were more potent than CBD in producing hypoactivity in mice. These analogues had relatively little effect on rectal temperature. Selected substitutions at C-10 also resulted in analogues that were partially effective in blocking delta 9-THC antinociceptive activity. This blockade was observed particularly in compound 10, which also showed unusually toxic properties. Incorporation of a seven-membered oxepin in the delta 9-THC structure eliminated cannabinoid activity although substitution of the pentyl side chain with a 1,2-dimethylheptyl in the oxepin 14b resulted in CNS depression in mice.
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PMID:Hashish: synthesis and central nervous system activity of some novel analogues of cannabidiol and oxepin derivatives of delta 9-tetrahydrocannabinol. 298 18

Intracellular recording techniques were used on neuromuscular junctions of the sartorius muscle of the frog, in vitro, to define the synaptic pharmacology of delta-9-tetrahydrocannabinol (THC), 11-hydroxy-THC and cannabidiol (CBD). The frequency of miniature endplate potentials was increased by THC, decreased by CBD and was unaffected by 11-hydroxy-THC, whereas the amplitude of the miniature endplate potentials was depressed by all three cannabinoids. In addition, the mean quantum content of the endplate potential (m) was first increased and then decreased by THC and 11-hydroxy-THC, but CBD produced only depression. Changes in m and the frequency of the miniature endplate potential indicated presynaptic sites of drug action and reduction of the amplitude of the miniature endplate potential suggested a postsynaptic site. The findings suggest possible mechanisms of action for the central excitatory and depressant properties of the cannabinoids.
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PMID:Effects of delta-9-tetrahydrocannabinol, 11-hydroxy-delta-9-tetrahydrocannabinol and cannabidiol on neuromuscular transmission in the frog. 302 65

The present studies examine some of the pharmacological effects of delta-9 (11)-tetrahydrocannabinol (delta 9-11-THC), an analog of delta-9-tetrahydrocannabinol (delta 9-THC). In tests with mice, delta 9-11-THC was similar to but less potent than delta 9-THC in producing hypothermia, analgesia, lethality and in reducing spontaneous activity. In dogs delta 9-THC but not delta 9-11-THC produced classical cannabimimetic signs including static ataxia, hyperreflexia, prancing and tail-tuck. delta 9-11-THC did produce central nervous system depression in 9 of the 15 dogs tested but the effects were not dose-related and appeared earlier and dissipated faster than the depressive effects induced by delta 9-THC. delta 9-THC but not delta 9-11-THC produced signs of ptosis, sedation and ataxia in rhesus monkeys. delta 9-THC also suppressed operant responding completely in four of four monkeys tested whereas in one monkey delta 9-11-THC did not do so up to doses as high as 5.0 mg/kg and was 8 to 100 times less potent in doing so in the other monkeys. When monkeys were pretreated with delta 9-11-THC the doses of delta 9-THC required to produce ptosis, sedation, ataxia and operant suppression were increased. However, when mice and dogs were pretreated with delta 9-11-THC the effects of delta 9-THC were not attenuated and usually were enhanced. The pharmacological profile of delta 9-11-THC is unusual in that it seems to have cannabimimetic activity in mice, noncannabimimetic-like effects in dogs and is perhaps devoid of cannabimimetic effects in rhesus monkeys. In addition, pretreatment with delta 9-11-THC attenuates the cannabimimetic effects of delta 9-THC in rhesus monkeys but not in mice or dogs.
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PMID:Studies on the agonistic activity of delta 9-11-tetrahydrocannabinol in mice, dogs and rhesus monkeys and its interactions with delta 9-tetrahydrocannabinol. 303 18

Intracellular recording techniques were used on spinal motoneurons in the cat in order to define the synaptic pharmacology of 11-hydroxy-delta-9-tetrahydrocannabinol (11-hydroxy-delta-9-THC), the principal metabolite of delta-9-tetrahydrocannabinol (delta-9-THC). The 11-hydroxy derivative increased the amplitude of excitatory postsynaptic potentials; such an excitatory response did not appear to be the result of changes in afferent input. The increase in excitatory postsynaptic potentials, however, may be accounted for by a rise in membrane resistance. The cannabinoid also concomitantly produced synaptic depression, as indicated by a rise in the firing threshold for the motoneuron action potential. The responses to 11-hydroxy derivative suggest synaptic sites and mechanisms of action; for instance, the data indicate that the cannabinoid affected postsynaptic conductance. Finally, the similarity between the synaptic effects of the 11-hydroxy derivative and those of delta-9-THC suggest that the metabolite may contribute to the pharmacological properties of its parent compound.
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PMID:Influence of 11-hydroxy-delta-9-tetrahydrocannabinol on spinal motoneurons in cat. 609 51

The effects of clomipramine HCl (15 mg kg-1 i.p.) on behaviour, body temperature and brain amines were investigated in rats that had been chronically treated twice daily with increasing doses of delta 9-tetrahydrocannabinol (delta 9-THC, 2-6 mg kg-1 i.v.). delta 9-THC produced a biphasic change in behaviour, stimulation followed by depression, and a pronounced hypothermia. Tolerance developed rapidly to these effects of delta 9-THC. Chronic treatment with delta 9-THC reduced the levels of homovanillic acid, 5-hydroxytryptamine and noradrenaline. The level of dopamine was not altered with chronic treatment and tolerance appeared to develop to the increased levels of 5-hydroxyindoleacetic acid induced by delta 9-THC. Injection of clomipramine, 12-14 h after 2, 5 or 10 days of delta 9-THC treatment induced characteristic changes in the rats behaviour which consisted of writhes, backward kicking, wet shakes, jumps ataxia and front paw and whole body tremor. The severity of the behavioural changes appeared to be dependent on the period of delta 9-THC administration and they were not accompanied by a change in body temperature or consistent changes in brain amines or metabolites. The results indicate that physical dependence on delta 9-THC may occur since clomipramine is able to precipitate changes in behaviour, indicative on an abstinence syndrome, in rats chronically treated with delta 9-THC. It is suggested that tryptaminergic mechanisms are altered during chronic delta 9-THC treatment and that clomipramine induces the behavioural changes by interacting with an altered tryptaminergic system.
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PMID:Time-course of the effects of chronic delta 9-tetrahydrocannabinol on behaviour, body temperature, brain amines and withdrawal-like behaviour in the rat. 612 98

Squirrel monkeys pressed a lever under a multiple interresponse-time greater than 28-sec, modified random-interval schedule which provided comparable frequencies and temporal distributions of food pellet presentation in the two components. Daily intramuscular administration of either 0.25 or 1.00 mg/kg delta 9-tetrahydrocannabinol resulted initially in suppression and/or disruption of responding and concomitant decreases in the frequency of food presentation in both components. Responding in both components next increased, resulting in recovery of baseline frequencies of pellet delivery during the random-interval component, but continued depression during the interresponse-time schedule. The drug-induced changes in responding under the interresponse-time schedule diminished with repeated injections, whereas response rates during the random-interval schedule sometimes remained elevated. Interresponse-time distributions under the interresponse-time schedule showed that with repeated administration of the drug only those characteristics which had the greatest effect on reinforcement frequency recovered to baseline levels. When drug injections were replaced by daily injections of the vehicle, responding was greatly disrupted only during the random-interval component. These findings are only partially consistent with other results which suggest aht tolerance development to the behavioral effects of delta 9-tetrahydrocannabinol is greatly enhanced if the drug initially produces reinforcement loss.
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PMID:Schedule-dependent tolerance to behavioral effects of delta 9-tetrahydrocannabinol when reinforcement frequencies are matched. 624 19


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