MARIJUANA UNDER THE MICROSCOPE

Some would say using marijuana in a medical setting is, ahem, a
half-baked idea with no possible benefits to society or suffering
patients.

Others might disagree, including the McGill research group that
recently received $235,000 from Health Canada in partnership with the
CIHR (Canadian Institute for Health Research) to scientifically prove
the medical worth of this popular plant.

Since the 1960s, scientists having been trying to ascertain the
medical benefits of one of North America's most common recreational
drugs. Consequently, there is a slew of anecdotal evidence attesting
to its use in alleviating suffering resulting from Crohn's disease,
partial spinal cord injuries and glaucoma.

Recent research has focused on the effects of marijuana on the immune
system and discomfort associated with cancer and AIDS chemotherapy.
Still, perhaps the most promising work has been done in the basic
science analysis of the mechanism of action that marijuana has in the
body.

Three Little Letters The active component thought to provide much of
the analgesic (pain modulation) and cognitive effects of marijuana is
called THC (tetrahydrocannabinol). While many scientists believe
there are other psychoactive compounds in cannabis, THC is the most
studied and best understood. Basically, when one smokes a joint or
uses some other ingestion device, the heat from the burning marijuana
leaves causes the THC to become aromatic (airborne) and enter your
lungs. Once inside, the THC enters the blood stream at the same
exchange point as oxygen. As any cigarette smoker or asthma inhaler
user will tell you, the alveoli are very efficient at allowing
chemicals to enter the blood. Less than two minutes after ingestion,
the blood flow will have distributed the tiny molecules of THC
throughout the body.

In healthy people, who are not in the process of being strangled, the
brain uses only 20 per cent of the oxygen available in the blood
cells. Hence, a lot of blood needs to get to your noggin in order to
meet the demand. And, like white on rice, the THC rides the chariot
of blood cells upward at a rapid clip. Once it reaches the brain, a
set of receptors are activated, causing the effects that have become
so familiar to pot-heads and invulnerable undergraduates, among other
sectors of our community.

The Receptors In much the same way as a key fits into a lock, THC
finds a home in what have been dubbed the cannibinoid receptors.
Commonly referred to in scientific literature as CB1 and CB2
(cannibinoid receptors 1 and 2), these receptors are abundant in the
brain. They are especially common in areas responsible for memory,
cognition and motor co-ordination. These regions are centred in the
cerebellum, hippocampus, hypothalamus and basal ganglia. For
scientists curious as to THC's effects, these receptors are crucial
to ongoing research and their presence is a cornerstone to explaining
marijuana's therapeutic effects.

Now, it might seem odd that we would have receptors for THC in our
brain. Why would evolution, or God, have placed these intricate
protein-carbohydrate structures up there just to get high?

Well, along with identifying the receptors for THC, researchers have
also elucidated the endogenous ligand (in English: the "key" for the
receptor "locks" made naturally in the body). This chemical is called
anandamide and is derived from fatty acids (the stuff in butter).

Ananamide is involved in numerous physiological processes including
pain modulation, control of movement, co-ordination, balance,
pleasure sensation, learning, cognition and memory. The current basic
science research is trying to resolve what impacts this
receptor-ligand (lock and key) mechanism, hormones or
neurotransmitters being the primary targets. Figuring out this
mechanism would mean being able to further our knowledge of these
incredibly complex systems, with the aim of eventually devising
treatments to aid in treating problems in these areas.

Those working in the area of cannibinoids are excited about future
prospects in this line of work. "Certainly not all the kinds of
pathways are worked out, and probably not all of the involved
molecules have been identified yet," commented Billy Martin at the
pharmacology and toxicology department of the Commonwealth University
in Richmond, Virginia. "But we're on the right track, characterising
the normal physiological pathways used by the cannibinoids to affect
pain modulation, control of movement, control of visceral sensation
and other processes."

Common Acute Effects Anyone who has smoked pot has stories of their
experiences that are both glorious and ignoble. Scientifically
speaking, however, the short-term effects were summed up very nicely
in 1996 in a paper by Dr. I.B. Adams and R. Martin titled Cannabis:
Pharmacology and Toxicology in Animals and Humans.

"Usually the mental and behavioural effects of marijuana consist of a
sense of well-being (often termed euphoria or a high), feelings of
relaxation, altered perception of time and distance, intensified
sensory experiences, laughter, talkativeness, and increased
sociability when taken in social settings. Impaired memory for recent
events, difficulty concentrating, dreamlike states, impaired motor
co-ordination, impaired driving and other psychomotor skills, slowed
reaction time, impaired goal-directed mental activity and altered
peripheral vision are common associated effects."

Glaucoma Perhaps the most convincing evidence for a medical use of
marijuana comes when one considers this common vision impairment.
Essentially, glaucoma causes one's vision to blur due to a film or
cataract that covers the eye. The cause is IOP (intraocular pressure)
which is an increased blood pressure in the optical region.

Recent research has found that, in a three-to-four-hour period after
administration of inhaled marijuana, the subjects' IOP was markedly
decreased. These results were seen in both patients with glaucoma and
those with normal IOPs. Also interesting to note was the fact that a
topically applied (cream form) of THC had no effect. The exact
mechanism of all other IOP inhibitory drugs is known but research in
the area of marijuana has been remarkably slow.

Despite lingering concerns regarding the administration of a drug
which had to be smoked, the American Academy of Ophthalmology had
this to say about using pot in the treatment of glaucoma (1992),
"There is clear evidence that marijuana (or its components) taken
orally or by inhalation can lower intra-ocular pressure."

AIDS and Cancer Chemotherapy Many of the strongest drugs used to
treat various cancers and AIDS boast long lists of uncomfortable side
effects. The most critical of these is "wasting," a term that
describes rapid weight loss caused by nausea and vomiting that
adversely affect many patients. The ravages of the disease are, in
many cases, not as uncomfortable as the toxic soup of medications
that are enlisted to aid in the body's defense efforts.

This is where marijuana comes to the rescue. With not a single
negative drug interaction reported, and hundreds if not thousands of
patients reporting miraculous alleviation of medication-related
suffering, marijuana may be the drug of choice to prevent wasting.

Indeed, AIDS patients serviced by the Compassion Clubs (marijuana
pharmacies) in Montreal and Vancouver have consistently toted the
benefits in terms of allowing them to eat and carry on their daily
routines. The medical establishment has taken these claims seriously
and is currently investigating the possibility of using cannabis in a
widespread manner to combat these side-effects.

Immune System THC also appears to have some immunosuppresent
properties. This may seem alarming, but in terms of making you
susceptible to that nasty cold, passing the joint and sharing your
buddy's saliva is likely to be much worse for you. Still, some
cell-mediated and humoral immune system responses may be slightly
impaired by heavy marijuana use. The data in this area is not
entirely clear or conclusive; some research actually points to an
enhancement of other parts of the immune system.

Scientifically speaking, marijuana's effect on the immune system is
an intriguing area of study. The auto-immune disorder multiple
sclerosis has shown some anecdotal evidence of being ameliorated by
weed. Also of note are results of experiments involving EAE
(experimental allergic encephalomyelitis). This is a disease that is
inducible in rats, which in many ways mimics the effects of MS. Here,
marijuana has been shown to modify the immune response and decrease
the severity of the disorder. This is certainly fascinating, as the
more we begin to understand the action of THC in the body, the better
we can apply its powers to the healing effort.

Science meets Politics and the Law While the Canadian government has
been more open to allowing marijuana to be studied and used in a
medical setting, our neighbour to the south has not been so
forthcoming. The DEA has not relented on marijuana's classification
as a Schedule-1 drug, insisting it has a high potential for abuse and
no medical uses. Many have pushed for downshifting of its status to
Schedule-2, where it would sit alongside other tightly controlled
prescription drugs such as morphine. These are drugs that have a high
potential for abuse but also some possible therapeutic effects.

On May 14, 2001 Justice Clarence Thomas had this to say about
changing the status of weed: "Marijuana has no medical benefits
worthy of an exception." The 8-0 U.S. Supreme Court ruling that the
manufacture and distribution of marijuana are illegal under all
circumstances has been a blow to hopeful investigators and the
substance's proponents in the scientific and medical communities.

On the other hand, a mere two months later, Canada relaxed its laws
regarding the availability of marijuana to severely and terminally
ill patients. As well, Health Canada has opened up the door to
research endeavours with its ambitious multi-million dollar
marijuana-growing facility in an abandoned mine under a northern
Manitoba lake.

With high-profile science publications like the Proceedings of the
National Academy of Science exhibiting work like Oxford's Leslie
Iverson's piece titled, "High Times for Cannabis Research," it seems
the tides may be changing regarding the uses of this banned
substance. It remains to be seen, however, what the current research
both McGill University and other universities here and abroad will
uncover with regards to this tantalising scientific discipline.