Introduction and Classification of Autacoids (Autacoids Part 1) | Dr. Shikha Parmar 

Introduction and Classification of Autacoids (Autacoids Part 1) by Dr. Shikha Parmar
Autacoids or "autocoids" are biological factors (molecules) which act as local hormones, have a brief duration, and act near their site of synthesis. The word autacoid comes from the Greek "autos" (self) and "Ecos" (relief; i.e., drug)
Although these are a local hormone, they do not have a characteristic feature of hormones-
Autocrine - Histamine, Prostaglandins, Serotonin Paracrine - Nitric Oxide (NO), Endothelin-1 (ET-1)
Histamine in the body stored in mast cells (present in the gut and lungs) and basophils and Plays a role in allergic/hypersensitivity reactions
(via activation of H1 receptors) other action
(1) In neurons in the CNS and peripheral nerves (H1)
(2) Plays a role as a Neurotransmitter/Neuromodulator
(3) Stimulates gastric acid secretion (via H2 receptors)
Description Source: Wikipedia