Cannabinoids Chemische Eigenschaften,Einsatz,Produktion Methoden
Acquired resistance
THC is rapidly and efficiently
absorbed by inhalation; it is absorbed into body tissue and slowly released back into circulation. Deuterium-labeled
THC has been detected in human plasma up to nearly 2 weeks postadministration. A major metabolite of THC is
11-hydroxy-?9
-THC. Evidence suggests that tolerance develops to THC and that THC does not generally lead to
physical dependence. Marijuana can produce impairment of performance, memory, and learning; controversy exists
over whether it produces an amotivational syndrome. There are many claims for the medicinal use of marijuana and
THC.
Mechanism of action
For many years, it was thought that cannabinoids were acting in a nonspecific manner, but in the early 1990s, two
populations of cannabinoid receptors were identified: CB-1, and CB-2. Human forms of these receptors have
been cloned. Both types are G protein–coupled, seven-helix transmembrane-spanning receptors. These receptors
are differentially expressed: CB-1 receptors, which may mediate the psychoactive effects of THC-related agents, are
found primarily in the brain, whereas CB-2 receptors, which possibly are involved in immunomodulatory actions, are
found almost exclusively in the periphery. The identification of such receptors suggested the possible existence of
endogenous ligands, and claims for several have been published. The best investigated of these is the eicosanoid
derivative arachidonylethanolamide or anandamide, which initially was isolated from porcine brain. Anandamide (Ki =
52 nM) binds at CB-1 receptors with an affinity similar to that of THC (46 nM). Related structures also have
been detected in brain, including docosatetraenylethanolamide (Ki = 34.4 nM) and homo-γ-linolenyllathanolamide (Ki= 53.4 nM). A related compound, palmitoylethanolamide, may show selectivity for CB-2 receptors. Anandamide seems to be a THC-like agent. Although the actions of anandamide may not be identical to those of THC, particularly regarding in vivo studies, differences may be related to the metabolic instability of anandamide. For example, in drug discrimination studies, a THC stimulus failed to consistently or reliably generalize to anandamide; however, the more metabolically stable methanandamide, a chain-methylated analogue of anandamide, produced THC-like effects.Furthermore, methanandamide has been used as a training drug, and the methanandamide stimulus generalizes to THC.
Clinical Use
The marijuana or cannabis plant represents one of the oldest and most widely used psychoactive substances in the
world. Botanically, there are three major species of the plant—Cannabis sativa, Cannabis indica, and Cannabis
ruderalis—and cannabis has been cultivated since approximately 6,000 BC. Reference is made to three
preparations, listed here in order of increasing potency: bhang, ganja, and hashish. Bhang typically refers to the
leaves and stems of the plant, ganja is prepared from the flowering tops of the plant, and hashish is the pure resin.
Although marijuana is active orally, inhalation by smoking is a more frequently used route of administration. One of
the major active constituents of the plant is ?9
-THC (often referred to simply as THC).
Cannabinoids Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
