Marijuana is derived from the hemp plant cannabis sativa which is grown in many tropical areas in the world. It is a green or grey mixture of dried, shedded flower and leaves. Marijuana is the most often used illegal drug in the United States. Most users roll loose marijuana into a cigarette called a “Joint” (William and Thomas, 2005). Some users mix marijuana into food or use it to brew tea, hash users either smoke the drug in a pipe or mix it with tobacco and smoke it as cigarette. Most researchers agreed that there is only one extract (sativa) with variant, while others believe that there are only three different extracts which include: Dranabinol (2,9-tetrahydrocannabinol), cannabinol and cannabidol (Agurell et al., 2000). Due to its nature as a substance of abuse, it is unlawful to posses or supply cannabis. Thus it is difficult to obtain precise estimate about the extent of its use. Data from 2013/2014 survey in Britain suggest that over 3.3 million people used cannabis that year (Chivite et al., 2014). From a New-Zealand birth cohort of 1265 children it was found that by the age of 21 nearly 70% has used cannabis (Fergusson and Hawood, 2011)
The heart is a muscular organ in all vertebrates which is responsible for pumping the blood by the repeated rhythmic contraction and involuntary muscles, it is supplied by the coronary circulation and enclosed by a sac known as the pericardium and it is surrounded by the lungs (Malton et al., 2009)
Enzyme markers of the heart disease can be assessed by estimation of a variety of enzymes such as creatine kinase (CK_MB), Lactate dehydrogenate (LDH) ,Alaninetransminase (ALT) and Aspartate transaninase (AST). A survey on 15 chronic marijuana smokers reveals that the values of AST, ALT,LDH, and Ck-MB were elevated following myocardial infarction when compared to non-smokers (Kew et al., 2010).
1.1 JUSTIFICATION
Marijuana smoking causes increased heart rate, myocardial infarction, increased blood pressure, acute coronary syndrome, increased cardiac muscle contraction and vascular complication which might cause injury to the heart. However, in a reviewed article for bulletin on narcotic, it was said that the use of cannabis causes portal hypertension which could impose threat to the cannabis users with hypertension, cerebrovascular disease or coronary artery disease (Khan et al., 2005). Three male patients (mean age 25 years) who were heavy cannabis smokers presented with transcients ischemic attack (TIA) shortly after cannabis abuse.
Ashton et al., (2007) in their paper review reported that cannabis has implicated cardiovascular processes including vasodilation, cardiac protection modulation of the bar receptors reflex in the control of systolic blood pressure and also the inhibition of neurotransmitter release in nucleus tractus solitaries. Previous studies have indicated that marijuana smoking leads to an elevation of CK-MB, LDH, AST and ALT following myocardial infraction when compared to non smokers as shown on 15 chronic marijuana smokers where their CK-MB, LDH, AST and ALT levels were elevated following myocardial infarction when compared to non-smokers (Kew et al., 2010).
A case reported in 2009 revealed that higher level of CK-MB, LDH, AST and ALT were observed in patients that were smoking marijuana and cigarette than in patients that were smoking marijuana alone. This theory has been challenged by several studies that found no correction at all.
This research is aimed at assessing the effects of marijuana smoking on the heart by using some enzyme markers of cardiac pathologies.
1.2 AIM AND SPECIFIC OBJECTIVES
To determine the effects of marijuana smoking on some cardiac enzyme in Albino rats