ABSTRACT
Endocannabinoid Metabolic Enzymes ......................................................... 127 5.9 Quantitative Methods to Study the mRNA Expression of
Endocannabinoid Metabolic Enzymes ......................................................... 128 5.9.1 N-Acyl-Phosphatidylethanolamine-Hydrolyzing
Phospholipase D ............................................................................... 129
The nding, in the early 1990s, of speci c G-protein-coupled receptors for the psychoactive component of Cannabis sativa, (−)-Δ9-tetrahydrocannabinol (THC) [1], led to the discovery of a whole endogenous signaling system now known as the endocannabinoid system (ECS). The ECS consists of the aforementioned cannabinoid receptors, the endocannabinoids (EC), and the proteins responsible for their metabolism. Mammalian tissues contain at least two types of cannabinoid receptors, CB1 and CB2 [2], and several types of endogenous compounds that activate these receptors have been identi ed (Figure 5.1). The two most studied EC are anandamide (AEA) [3] and 2-arachidonoyl-glycerol (2-AG) [4,5]. These molecules are biosynthesized via the cleavage of their membrane lipid precursors, N-arachidonoylphosphatidylethanolamine (N-ArPE) and diacylglycerols (DAG). The EC are inactivated by intracellular hydrolyzing enzymes, fatty acid amide hydrolase (FAAH), and monoacylglycerol lipases (MAGL) ([6] for review). In this chapter, we review some of the methodologies necessary to study the ECS. In particular, we focus our attention on the analytical and enzymatic procedures that allow for the study of the regulation of EC levels and have helped in establishing the physiological role of the ECS and its involvement in several pathological conditions.
