Pargyline is a monoamine oxidase B inhibitor (MAOIs). This drug has antihypertensive properties and is, thus, indicated in the treatment of moderate to severe hypertension. Pargyline inhibits the breakdown of monoamine neurotransmitters, leading to an increase in their concentration in the neurons. There are 2 isoforms of this protein: A and B. The first one is found in cells located in the periphery and breakdown serotonin, norepinephrine, epinephrine, dopamine, and tyramine. The second one, the B isoform, breakdowns phenylethylamine, norepinephrine, epinephrine, dopamine, and tyramine. This isoform is found in the extracellular tissues and mainly in the brain. The mechanism of action of the MAOIs is still not determined, it is thought that they act by increasing free serotonin and norepinephrine concentrations and/or altering the concentrations of other amines in the CNS. MAO A inhibition is thought to be more relevant to antidepressant activity than the inhibition caused by MAO B. Selective MAO B inhibitors have no antidepressant effects. Pargyline functions by inhibiting the metabolism of catecholamines and tyramine in the presynaptic neuron. In general, catecholamines cause physiological changes to give the body the ability to respond to a fight-or-flight alarm. The typical effects are increases in heart rate, blood pressure, and blood glucose levels.

Pargyline Pathway References