✍ Scribed by R. D. Blevins; J. D. Regan
No coin nor oath required. For personal study only.
The principal psychoactive component of marihuana is A-9-tetrahydrocannabinol. This compound at 10 -5 molar concentration in the medium of human cell cultures appeared to inhibit DNA, RNA, and protein synthesis by 50, 40, and 30% respectively, as measured by incorporation of radioactive precursors into acid-insoluble cell fractions in human diploid fibroblasts, human neuroblastoma cells, and mouse neuroblastoma cells. While A-9-tetrahydrocannabinol inhibited semiconservative DNA synthesis, it had no effect on DNA repair synthesis in human cells as assayed by the photolysis of 5-bromodeoxyuridine incorporation into DNA during repair after ultraviolet radiation damage. A-9-tetrahydrocannabinol also had no effect on rejoining of DNA single-strand breaks induced by F-rays. The nonspecificity of the inhibition of macromolecular synthesis by A-9-THC suggested a possible interference with uptake of radioactive precursors. However, experimentation has shown that this depression of macromolecular synthesis cannot be accounted for by reduced transport of radioactive precursors into the cell because the rate of transport of these precursors into the cell is essentially the same in the presence or absence of A-9-THC.
Pool sizes of macromolecular precursors as measured radioisotopically (3nthymidine, 3H-uridine, 14C-leucine) appear to be reduced about 50%, and this reduced pool size could fully account for the reduced macromolecular synthesis seen in the presence of A-9-THC. We do not know what causes this apparent reduction of pool sizes in the presence of A-9-THC.
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Twenty five volunteers received (-) trans-delta9-tetrahydrocannabinol (THC) (320 microgram/kg) or placebo (both orally, T0), and, 60 min later, they consumed an ethanolic beverage (0.54 g/kg) or placebo. The effects of this medication were measured at T1 (100 min after THC ingestion), T2 (160 min),
A three-way crossover study was performed to determine the influence of A'-tetrahydrocannabinol (THC) and ethanol (EtOH) separately upon phencyclidine (PCP) disposition in dogs. Seven dogs were given three single dose treatments: 1.5 mg PCP kg-' i.v., 1.5mg PCP kg-' i.v. with 0.4mgkg-' THC i.v., and
The onset and duration of tolerance to three effects of A9-tetrahydrocannabinol (A9-THC) given orally to mice were compared. The effects of A9-THC studied were: hypothermia, the depression of intestinal motility and the effect on spontaneous locomotor activity. When mice were dosed and tested at 24
The influences of delta 9-tetrahydrocannabinol (THC) and cannabidiol on electrically evoked cortical potentials of conscious rats with chronically implanted electrodes were investigated. Specifically, the cannabinoids' effects on a transcallosal evoked response were compared with those of ethosuximi