Marijuana is the most commonly abused drug. A dry, shredded green/brown mix of flowers, stems, seeds, and leaves of the plant Cannabis sativa, it usually is smoked as a cigarette (joint, nail), or in a pipe (bong). It also is smoked in blunts, which are cigars that have been emptied of tobacco and refilled with marijuana, often in combination with another drug. It might also be mixed in food or brewed as a tea. As a more concentrated, resinous form it is called hashish and, as a sticky black liquid, hash oil. Marijuana smoke has a pungent and distinctive, usually sweet-and-sour odor. There are treatment for marijuana addiction.
The main active chemical in marijuana is THC (delta-9-tetrahydrocannabinol). The membranes of certain nerve cells in the brain contain protein receptors that bind to THC. Once securely in place, THC kicks off a series of cellular reactions that ultimately lead to the high that users experience when they smoke marijuana.
On the street is known as “grass”, “pot”, “weed”, “bud”, “Mary Jane”, “dope”, “indo”, “hydro”, etc.
SHORT-TERM EFFECTS
When marijuana is smoked, its effects begin immediately after the drug enters the brain and last from 1 to 3 hours. If marijuana is consumed in food or drink, the short-term effects begin more slowly, usually in 1/2 to 1 hour, and last longer, for as long as 4 hours. Smoking marijuana deposits several times more THC into the blood than does eating or drinking the drug.
Within a few minutes after inhaling marijuana smoke, an individual’s heart begins beating more rapidly, the bronchial passages relax and become enlarged, and blood vessels in the eyes expand, making the eyes look red. As THC enters the brain, it causes a user to feel euphoric by acting in the brain’s reward system, areas of the brain that respond to stimuli such as food and drink as well as most drugs of abuse.
A marijuana user may experience pleasant sensations, colors and sounds may seem more intense, and time appears to pass very slowly. The user’s mouth feels dry, and he or she may suddenly become very hungry and thirsty. His or her hands may tremble and grow cold. The euphoria passes after awhile, and then the user may feel sleepy or depressed. Occasionally, marijuana use produces anxiety, fear, distrust, or panic.
Someone who smokes marijuana regularly may have many of the same respiratory problems that tobacco smokers do, such as daily cough and phlegm production, more frequent acute chest illnesses, a heightened risk of lung infections, and a greater tendency toward obstructed airways. Cancer of the respiratory tract and lungs may also be promoted by marijuana smoke. Marijuana has the potential to promote cancer of the lungs and other parts of the respiratory tract because marijuana smoke contains 50 percent to 70 percent more carcinogenic hydrocarbons than does tobacco smoke.
We strongly recommend to everyone reading this article to stay out of marijuana use, however, if you or someone close to you have problems with drug addiction, we suggest you to visit Drug Rehab Treatment programs in Canada.
October 13th, 2009
The active ingredient in marijuana cuts tumor growth in common lung cancer in half and significantly reduces the ability of the cancer
to spread, say researchers at Harvard University who tested the chemical in both lab and mouse studies.
They say this is the first set of experiments to show that the compound, Delta-tetrahydrocannabinol (THC), inhibits EGF-induced growth
and migration in epidermal growth factor receptor (EGFR) expressing non-small cell lung cancer cell lines. Lung cancers that over-express
EGFR are usually highly aggressive and resistant to chemotherapy.
THC that targets cannabinoid receptors CB1 and CB2 is similar in function to endocannabinoids, which are cannabinoids that are naturally
produced in the body and activate these receptors. The researchers suggest that THC or other designer agents that activate these receptors
might be used in a targeted fashion to treat lung cancer.
“The beauty of this study is that we are showing that a substance of abuse, if used prudently, may offer a new road to therapy against
lung cancer,” said Anju Preet, Ph.D., a researcher in the Division of Experimental Medicine.
Acting through cannabinoid receptors CB1 and CB2, endocannabinoids (as well as THC) are thought to play a role in variety of biological
functions, including pain and anxiety control, and inflammation. Although a medical derivative of THC, known as Marinol, has been approved
for use as an appetite stimulant for cancer patients, and a small number of U.S. states allow use of medical marijuana to treat the same
side effect, few studies have shown that THC might have anti-tumor activity, Preet says. The only clinical trial testing THC as a treatment
against cancer growth was a recently completed British pilot study in human glioblastoma.
In the present study, the researchers first demonstrated that two different lung cancer cell lines as well as patient lung tumor samples
express CB1 and CB2, and that non-toxic doses of THC inhibited growth and spread in the cell lines. “When the cells are pretreated with
THC, they have less EGFR stimulated invasion as measured by various in-vitro assays,” Preet said.
Then, for three weeks, researchers injected standard doses of THC into mice that had been implanted with human lung cancer cells,
and found that tumors were reduced in size and weight by about 50 percent in treated animals compared to a control group.
There was also about a 60 percent reduction in cancer lesions on the lungs in these mice as well as a significant reduction in
protein markers associated with cancer progression, Preet says.
Although the researchers do not know why THC inhibits tumor growth, they say the substance could be activating molecules that
arrest the cell cycle. They speculate that THC may also interfere with angiogenesis and vascularization, which promotes cancer growth.
Preet says much work is needed to clarify the pathway by which THC functions, and cautions that some animal studies have shown that
THC can stimulate some cancers. “THC offers some promise, but we have a long way to go before we know what its potential is,”
she said.
October 13th, 2009
One of several studies about cancer and cannabis
http://www.webmd.com/cancer/news/20071226/pot-slows-cancer-in-test-tube