Amine Autacoids Quiz and Flashcards

What type of molecules are autacoids?

Which receptors do autacoids NOT act on?

What is the other name for serotonin?

Why are ergot alkaloids included in this section?

What is the classification of histamine and serotonin?

What is the primary source of histamine in the body?

Which enzyme is involved in the metabolism of histamine?

What is the role of histamine in the stomach?

What is the major metabolite of histamine that can be measured in the urine?

Which condition is characterized by excess production of histamine?

Autacoids

Autacoids are endogenous molecules that don't fall into traditional autonomic groups.
They have powerful pharmacologic effects on smooth muscle and other tissues, but don't act on cholinoceptors or adrenoceptors.

Histamine

Histamine is an important amine autacoid formed from the amino acid histidine.
It is stored in high concentrations in vesicles in mast cells, enterochromaffin cells in the gut, some neurons, and a few other cell types.
Histamine is metabolized by the enzymes monoamine oxidase and diamine oxidase.
Excess production of histamine in the body can be detected by measuring its major metabolite, imidazole acetic acid in the urine.
Histamine plays a pathophysiologic role in:
Seasonal rhinitis (hay fever)
Urticaria
Angioneurotic edema (along with bradykinin)
Histamine also plays a physiologic role in:
Controlling acid secretion in the stomach
As a neurotransmitter

Serotonin (5-HT)

Serotonin is another important amine autacoid.
Ergot alkaloids are a heterogeneous group of drugs that interact with serotonin receptors, dopamine receptors, and alpha receptors.

Other

Bradykinin is a peptide that plays an important role in angioneurotic edema.

Learn about autacoids, endogenous molecules with powerful pharmacologic effects on smooth muscle and other tissues. Discover the importance of histamine and serotonin, and how ergot alkaloids interact with receptors. Test your knowledge on these autonomic molecules.