autocoids

Question 1

Etymology of ‘Autacoid’

Answer 1

Derived from Greek ‘Autos’ (Self) and ‘Akos’ (Remedy/Healing substance).

Question 2

Defining characteristic of Autacoids

Answer 2

Produced and act locally (paracrine) at the site of synthesis; brief duration of action.

Question 3

How do Autacoids differ from Hormones?

Answer 3

Hormones are produced in specific glands and travel through blood; Autacoids are made by many cells and act locally.

Question 4

Main chemical classification of Autacoids

Answer 4

1. Amine autacoids 2. Lipid-derived (Eicosanoids) 3. Peptide autacoids.

Question 5

Examples of Amine autacoids

Answer 5

Histamine and 5-Hydroxytryptamine (Serotonin).

Question 6

Examples of Lipid-derived autacoids

Answer 6

Prostaglandins (PG), Leukotrienes (LT), and Platelet Activating Factor (PAF).

Question 7

Examples of Peptide autacoids

Answer 7

Plasma kinins (Bradykinin, Kallidin) and Angiotensins.

Question 8

Source amino acid for Histamine synthesis

Answer 8

L-Histidine (via Histidine decarboxylase).

Question 9

Source amino acid for Serotonin synthesis

Answer 9

L-Tryptophan (via Tryptophan hydroxylase).

Question 10

Primary precursor for Eicosanoids (Lipid autacoids)

Answer 10

Arachidonic acid (derived from membrane phospholipids).

Question 11

Which autacoid is also called ‘Local Hormone’?

Answer 11

Autacoids in general (most commonly applied to Histamine and Serotonin).

Question 12

Name ‘Other’ autacoids sometimes included in classification

Answer 12

Cytokines (IL-1, TNF-alpha) and Gastrin/Somatostatin.