Beach_Leec's other health problems

[chrish]

Effects on the Heart

One study has indicated that a user’s risk of heart attack more than quadruples in the first hour after smoking marijuana. The researchers suggest that such an effect might occur from marijuana’s effects on blood pressure and heart rate and reduced oxygen-carrying capacity of blood.

Effects on the Lungs

A study of 450 individuals found that people who smoke marijuana frequently but do not smoke tobacco have more health problems and miss more days of work than nonsmokers. Many of the extra sick days among the marijuana smokers in the study were for respiratory illnesses.

Even infrequent use can cause burning and stinging of the mouth and throat, often accompanied by a heavy cough. 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 illness, a heightened risk of lung infections, and a greater tendency to obstructed airways.

Cancer of the respiratory tract and lungs may also be promoted by marijuana smoke. A study comparing 173 cancer patients and 176 healthy individuals produced strong evidence that smoking marijuana increases the likelihood of developing cancer of the head or neck, and the more marijuana smoked the greater the increase. A statistical analysis of the data suggested that marijuana smoking doubled or tripled the risk of these cancers.

Marijuana use has the potential to promote cancer of the lungs and other parts of the respiratory tract because it contains irritants and carcinogens. In fact, marijuana smoke contains 50 to 70 percent more carcinogenic hydrocarbons than does tobacco smoke. It also produces high levels of an enzyme that converts certain hydrocarbons into their carcinogenic form—levels that may accelerate the changes that ultimately produce malignant cells. Marijuana users usually inhale more deeply and hold their breath longer than tobacco smokers do, which increases the lungs’ exposure to carcinogenic smoke. These facts suggest that, puff for puff, smoking marijuana may increase the risk of cancer more than smoking tobacco.

Other Health Effects

Some of marijuana's adverse health effects may occur because THC impairs the immune system’s ability to fight off infectious diseases and cancer. In laboratory experiments that exposed animal and human cells to THC or other marijuana ingredients, the normal disease-preventing reactions of many of the key types of immune cells were inhibited. In other studies, mice exposed to THC or related substances were more likely than unexposed mice to develop bacterial infections and tumors.

Effects of Heavy Marijuana Use on Learning and Social Behavior

Depression, anxiety, and personality disturbances are all associated with marijuana use. Research clearly demonstrates that marijuana use has potential to cause problems in daily life or make a person’s existing problems worse. Because marijuana compromises the ability to learn and remember information, the more a person uses marijuana the more he or she is likely to fall behind in accumulating intellectual, job, or social skills. Moreover, research has shown that marijuana’s adverse impact on memory and learning can last for days or weeks after the acute effects of the drug wear off.

Students who smoke marijuana get lower grades and are less likely to graduate from high school, compared to their non-smoking peers. In one study, researchers compared marijuana-smoking and non-smoking 12th-graders’ scores on standardized tests of verbal and mathematical skills. Although all of the students had scored equally well in 4th grade, the marijuana smokers’ scores were significantly lower in 12th grade.

A study of 129 college students found that, for heavy users of marijuana (those who smoked the drug at least 27 of the preceding 30 days), critical skills related to attention, memory, and learning were significantly impaired even after they had not used the drug for at least 24 hours. The heavy marijuana users in the study had more trouble sustaining and shifting their attention and in registering, organizing, and using information than did the study participants who had used marijuana no more than 3 of the previous 30 days. As a result, someone who smokes marijuana once daily may be functioning at a reduced intellectual level all of the time.

More recently, the same researchers showed that the ability of a group of long-term heavy marijuana users to recall words from a list remained impaired for a week after quitting, but returned to normal within 4 weeks. An implication of this finding is that some cognitive abilities may be restored in individuals who quit smoking marijuana, even after long-term heavy use.

Workers who smoke marijuana are more likely than their coworkers to have problems on the job. Several studies associate workers' marijuana smoking with increased absences, tardiness, accidents, workers' compensation claims, and job turnover. A study of municipal workers found that those who used marijuana on or off the job reported more "withdrawal behaviors"—such as leaving work without permission, daydreaming, spending work time on personal matters, and shirking tasks—that adversely affect productivity and morale.

Effects on Pregnancy

Research has shown that babies born to women who used marijuana during their pregnancies display altered responses to visual stimuli, increased tremulousness, and a high-pitched cry, which may indicate problems with neurological development. During infancy and preschool years, marijuana-exposed children have been observed to have more behavioral problems and poorer performance on tasks of visual perception, language comprehension, sustained attention, and memory. In school, these children are more likely to exhibit deficits in decision-making skills, memory, and the ability to remain attentive.

Addictive Potential

Long-term marijuana use can lead to addiction for some people; that is, they use the drug compulsively even though it often interferes with family, school, work, and recreational activities. Drug craving and withdrawal symptoms can make it hard for long-term marijuana smokers to stop using the drug. People trying to quit report irritability, sleeplessness, and anxiety(38). They also display increased aggression on psychological tests, peaking approximately one week after the last use of the drug(39).

[beachguy_inthongs]

Lungs-
Experiments were conducted to investigate the bronchodilating action of delta-9-tetrahydrocannabinol (THC) using normal human lung tissue obtained post mortem. Isolated rings of human bronchioles contracted to histamine, carbachol, and prostaglandin F(2a)(PGF(2a)) and relaxed to isoproterenol. THC (5 X 10(-4)M) did not alter the responses of the bronchial rings to histamine, whereas methapyrilene (10(-6)M) antagonized these responses. Atropine (2 X 10(-6)M) had a highly significant effect on the responses of the bronchioles to carbachol: there was also a significant effect of THC (5 X 10(-4)M), but to a much lesser extent than atropine. Propranolol (10(-6)M) pretreatment significantly antagonized the relaxant responses of the bronchioles to isoproternol: THC antagonized these responses to a smaller degree. Incubation with THC did not cause relaxation of resting tissues or tissues in which a spasm had been induced. These data suggest that THC does not have significant direct effects in human bronchial smooth muscle and that bronchoactivity observed in vivo is likely to be of a nondirect or central origin.

Arch Int Pharmacodyn Ther. 1980 Jul;246(1):71-83.
Delta-9-tetrahydrocannabinol on isolated human bronchioles.
* Orzelek-O'Neil RM,
* Goodman FR,
* Forney RB.

Heart-
The mechanisms by which cannabinoids alter coronary vascular tone and cardiac performance are controversial. We investigated the effects of various cannabinoids in spontaneously beating Langendorff-perfused rat hearts. Bolus injections of anandamide (0.1-1 micromol) caused no change in coronary flow (CF) or left ventricular systolic pressure (LVSP). In hearts preperfused with vasopressin to induce vasoconstrictor tone, anandamide or the selective CB1 receptor agonist ACEA (1-100 nmol) dose-dependently increased CF by up to 267% and LVSP by 20 mm Hg. The metabolically stable endocannabinoid derivatives, R-methanandamide and noladin ether, displayed similar effects. In contrast, Delta-THC (10-100 nmol), the major psychoactive ingredient of cannabis, strongly decreased CF and LVSP. The CB2 receptor agonist JWH-133 (10-100 nmol) elicited vasodilator and positive inotropic effects only at higher doses. The CB1 antagonists SR141716A and AM-251 as well as the potassium channel inhibitors tetraethylammonium and iberiotoxin blocked the anandamide-induced increases in CF and LVSP, whereas the CB2 antagonist SR144528 and the putative "CB3 antagonist" O-1918 did not have an inhibitory effect. Immunohistochemistry revealed the presence of cardiac CB1 but no CB2 receptors. Anandamide and 2-arachidonoylglycerol were detected in heart tissue. However, combined application of fatty acid amidohydrolase inhibitors and the transport inhibitor AM-404 to augment tissue levels of endocannabinoids was without effect on CF or LVSP. We conclude that in the rat isolated heart with reestablished vasoconstrictor tone, cannabinoids including anandamide elicit coronary vasodilation and a secondary increase in contractility via CB1 receptors and potassium channels.

J Cardiovasc Pharmacol. 2005 Sep;46(3):348-55.Click here to read Links
Coronary vasodilator effects of endogenous cannabinoids in vasopressin-preconstricted unpaced rat isolated hearts.

* Wagner JA,
* Abesser M,
* Karcher J,
* Laser M,
* Kunos G.

Department of Internal Medicine I, Center of Cardiovascular Medicine, University of Wurzburg, Wurzburg, Germany. wagner_j@klinik.uni-wuerzberg.de

Check your sources, wiseguy.