hempity
Premier Member
Registered on
Feb-21-2000
More User Info
|
Message #10073 posted by hempity (Info) May 12, 2006 15:53:43 ET
The endogenous cardiac cannabinoid system: a new protective mechanism
against myocardial ischemia
Lamontagne, D., P. Lepicier, et al. (2006). Arch Mal Coeur Vaiss 99 (3) Mar:
242-6.
The pharmacological (and recreational) effects of cannabis have been known
for centuries. However, it is only recently that one has identified two subtypes
of G-protein-coupled receptors, namely CB1 and CB2-receptors, which
mediate the numerous effects of delta9-tetrahydrocannabinol and other
cannabinoids. Logically, the existence of cannabinoid-receptors implies that
endogenous ligands for these receptors (endocannabinoids) exist and exert a
physiological role. Hence, arachidonoylethanolamide (anandamide) and sn-2
arachidonoylglycerol, the first two endocannabinoids identified, are formed
from plasma membrane phospholipids and act as CB1 and/or CB2 agonists.
The presence of both CB1 and CB2-receptors in the rat heart is noteworthy.
This endogenous cardiac cannabinoid system is involved in several
phenomena associated with cardioprotective effects. The reduction in infarct
size following myocardial ischemia, observed in rats exposed to either LPS or
heat stress 24 hours before, is abolished in the presence of a CB2-receptor
antagonist. Endocannabinoids and synthetic cannabinoids, the latter through
either CB1 or CB2-receptors, exert direct cardioprotective effects in rat
isolated hearts. The ability of cannabinoids to reduce infarct size has been
confirmed in vivo in anesthetized mice and rats. This latter effect appears to
be mediated through CB2-receptors. Thus, the endogenous cardiac
cannabinoid system, through activation of CB2-receptors, appears to be an
important mechanism of protection against myocardial ischemia.
http://www.ccicnewsletter.com/index....ewsletter&=SID
|
