Marijuanas delta-9-tetrahydrocannabinol (THC)

Marijuana is a unique and controversial drug. It is a most popular psychoactive drug that is easily accessible and relatively inexpensive. Marijuana is often considered a recreational drug despite its illegal status. It is illegal because there are many uncertainties surrounding this substance. In fact, some favor the use of marijuana for medicinal purposes while others oppose. Opponents of marijuana insist that legal approval will result in serious personal and social problems.

There are three species of Marijuana. The most common and most psychoactive is a prepared mixture of the hemp plant, Cannabis sativa. Cannabis indica is known to be less potent and Cannabis ruderalis has virtually no psychoactive ingredients. Cannabis sativa will be analyzed in detail since it is the most commonly used species. This plant grows wild but it can be cultivated in temperate as well as tropical areas. Cannabis products can be smoked in pipes or cigarettes. They can also be ingested with food. Manufactured products range from paper to ink.

Every plant varies slightly in composition and the different parts of the plant vary in chemical constituents. In 1993 researchers discovered 400 to 500 chemicals. Some of the major types of chemical constituents in marijuana preparations include acids, alcohols, aldehydes, and amino acids. Cannabinoids, esters, enzymes, glycoproteins, hydrocarbons, ketones, lactones, nitrogenous compounds, phenols, pigments, proteins, sugars, steroids, terpenes, and vitamins are others. These are among some of the naturally occurring chemicals in marijuana and were derived from the Institute of Medicine and the Marijuana Project from the University of Mississippi. Furthermore, researchers have found that when cannabis is burned, additional chemicals are formed and may be found in the gas and smoke. One of the chemicals produced is benzopyrene, which is a known carcinogen. It is approximately 70% more abundant in marijuana smoke than in tobacco smoke.

Only about 30 of the chemicals in marijuana have been studied extensively for their psychoactive effects. Of these delta-9-tetrahydrocannabinol (THC) is known to be the most psychoactive chemical. This chemical is converted into over 60 other psychoactive metabolites by the liver (Carroll 1993). These chemical reactions, however, have either proved insignificant or not enough research has been conducted to prove their importance. Researchers have been mostly concerned with the interaction of THC in the human body.

THC concentration in the human body depends on many factors. First of all, THC concentration varies throughout the plant. Of the three different species of marijuana, Cannabis sativa has the highest level of THC. Its levels vary depending on the method of cultivation. Among the factors that influence THC concentration in the plant itself are climate, soil condition, harvesting process, and any added "ingredients" to the soil (Grinspon 1997).

These "ingredients" can be harmful when they enter the human body. One of these ingredients is paraquat, a herbicide that is often sprayed by legal authorities with the intent to destroy the harvest. The problem with this method that is widely to enforce the war on drugs by legal authorities is that this contaminated herb can easily reach the streets where it is daily dealt and consumed. Paraquat can have serious effects on the kidneys, heart, central nervous system, skeletal muscles and spleen. Thus, contaminated marijuana can create serious health problems.

The growing method for cultivating marijuana also affects THC concentration levels in the plant. The sinsemilla growing technique has been the most revolutionary since it increases THC concentration. This technique requires separating female plants from male plants before pollination. Female plants produce more THC when unpollinated and seedless. Thus, THC content in marijuana varies from 3.6% to 15% depending upon the method used to cultivate the plant (Grinspoon 1997). The sinsemilla preparations contain the highest levels of THC. These preparations contribute to higher levels of intoxication and to other potential consequences.

Method of consumption also affects the effects of THC on the brain. If smoked, THC is rapidly absorbed by the blood in the lungs and transported to the brain in less than 30 seconds. The same mount, if ingested, takes two to three hours for effects to show. Marijuana may also be consumed with food or by itself. In this case, the effects take longer to show (2-3 hors). Absorption takes much longer since it must go through the digestive tract before it can pass to the blood brain barrier. However, the amount of THC, if ingested, can not be controlled as it is smoked. Smokers of marijuana can generally control the "high" state by monitoring the amount of "hits" or times they inhale.

As mentioned earlier, once the active chemical enters the body, the liver begins to change the THC to many chemicals. These chemicals are known as metabolites. They produce different effects that may vary in relation to the dose administered. Thus, marijuana can induce a sedating effect or it can serve as a simulator. These effects are dependent on the variety and amount of chemical absorbed in the brain. As a depressant, it can be quite relaxing, creating drowsiness and or feelings of detachment. As a stimulant, on the other hand, it can increase alertness. It can produce sensations, auditory distortions or visual delusions.

Psychological and behavioral effects, therefore, are attributed to several variables. Among these are dose, preparation, route of administration and quantity of THC concentration in the plant. The effects are also dependent on the user. That is, the user's personalities, psychological state, motivation, mind set and prior experience with the drug. These psychedelic effects are dependent in grand part on the mood of the consumer as well as the surroundings.

Biological factors that determine the degree of intoxication include drug absorption, distribution, metabolism and elimination by the liver and other body organs. These functions vary from person to person and so do the effects and length of intoxication of the individual. Metabolism, for example, is a process in which chemical changes occur in the body, that alter drugs and convert them to substances that can be eliminated by the body. A special system of enzymes that function primarily in the liver cells carries out these "cleansing" reactions. This process is called biotransformation. The blood then carries these "new" substances to the kidneys where they are expelled. They are finally eliminated through urine.

The half-life of THC concentration ranges from .8 to 9.8 days. This varies from person to person, depending primarily on metabolism and frequency of use. Infrequent users with fast metabolism will have the shortest detection time. Furthermore, THC is fat-soluble and gets stored in the fat cells. Since fat cells secrete THC metabolites over an extended period of time, cleaning out the body from this substance is difficult.

Concentration of THC can be detected through the amount of metabolites in urine. Enzyme Multiplied Immunoassay Technique (EMIT) is the most common way to determine these concentrations. Decreasing marijuana detection times can be accomplished by increasing metabolism through exercise and or a high calorie diet. Furthermore, lightweight people usually experience greater effects and less difficulty expelling the chemicals. Heavier people, on the other hand, have greater quantities of body fluids. The greater concentrations of body fluids, including blood, dilute the drug.

from sulcus.berkeley.edu