Autocoids and Histamine

Front

What is the origin of the word 'Autocoid'?

Back

Derived from Greek: 'Autos' meaning self and 'Akos' meaning healing substance or remedy.

Front

What are autocoids?

Back

Diverse substances produced by various cells in the body with intense biological activity.

Front

What is a unique attribute of autocoids?

Back

They act locally at the site of synthesis and release, often referred to as local hormones.

Front

How do autocoids differ from hormones?

Back

Autocoids act locally and have short-lived effects, while hormones are released into the bloodstream and act on distant organs with longer-lasting effects.

Front

Name the five classical types of autacoids.

Back

1. Amine autacoids (e.g., Histamine, Serotonin) 2. Lipid-derived autacoids (e.g., Prostaglandins, Leukotrienes) 3. Peptide autacoids (e.g., Bradykinin, Angiotensin) 4. Cytokines (e.g., interleukins, TNF-α) 5. Several peptides (e.g., gastrin, somatostatin).

Front

Where is histamine primarily located in the body?

Back

Histamine is mostly found in mast cells, particularly in the skin, gastric and intestinal mucosa, lungs, liver, and placenta.

Front

What is the difference between mast cell histamine and non-mast cell histamine?

Back

Mast cell histamine is released during allergic reactions causing symptoms like swelling and itching, while non-mast cell histamine is involved in normal body functions like stomach acid secretion.

Front

How is histamine synthesized?

Back

Histamine is synthesized locally from the amino acid histidine.

Front

What are the main functions of H1 receptors?

Back

H1 receptors cause allergy symptoms such as itching, swelling, sneezing, and runny nose.

Front

What is the role of H2 receptors?

Back

H2 receptors help release acid in the stomach for digestion.