Posted by Adam on December 8, 2000, at 20:31:34
In reply to What I know about MAO and MAOIs, posted by Adam on December 8, 2000, at 14:48:48
Before beginning a discussion of MAOIs, it might be helpful to briefly touch on some of the chemicals it is thought to influence in the body.
Biogenic amines can be defined as a class of compounds, somehow derived from ammonia (NH3), and produced by living organisms. This classification excludes the amino acids, which are structurally similar, and are generally precursors of the biogenic amines. As the name implies, biogenic monoamines contain a single amine group, and have the general structure:
..............H.......R1....
...............|......./.........
........R - C - N.........
...............|.......\.........
..............H.......R2....(The R1 & R2 might represent an H, or a carbon chain. My apologies for the little dots as spacing).
Neurotransmitters are hormones (molecular messengers that send signals from one cell to another) that serve to transmit nervous impulses between neurons and neurons and other excitable cells (like skeletal muscle cells). Many of the biogenic monoamines serve as neurotransmitters in the central nervous system (CNS). Some examples:
Catecholamines: These are derivatives of the amino acid tyrosine. They include epinephrine (adrenaline), norepinephrine (NE, also called noradrenaline) and dopamine (DA). DA and NE are thought to be especially potent regulators of affect, cognition, appetitive behaviors (think of the four F’s: Fighting, Fleeing, Feeding, and, uh, Sex) as well as a number of other CNS functions.
Serotonin: Also called 5-hydroxytryptamine or 5-HT. An indolamine, it is a derivative of the amino acid tryptophan. It is thought to be an important regulator of mood, sleep, and many functions of the autonomic nervous system. (To be picky about chemical nomenclature, although serotonin is included in the category of monoamines for most purposes, it contains another amine within the indole group).
Phenylethylamine: (PEA), also called phenethylamine. It is a derivative of the amino acid phenylalanine. It seems to be especially involved in the neurochemistry of "bliss", and is a mediator of the sensation of being in love. It is also found naturally in chocolate.
Histamine: An imidazolamine, it is a derivative of the amino acid histidine. In the CNS the function of histamine is not entirely understood, though it seems to be involved in the regulation of functions as diverse as locomotor activity and nociception (perceiving pain.)
All of the above, in addition to sharing some common chemical properties, are also substrates for monamine oxidase.
poster:Adam
thread:50196
URL: http://www.dr-bob.org/babble/20001130/msgs/50215.html