Description:

Autacoids or "autocoids" are biological factors (molecules) which act like local hormones, have a brief duration, and act near their site of synthesis. The word autacoid comes from the Greek words "autos" (self) and "acos" (relief; i.e., drug). The effects of autacoids are primarily local, though large quantities can be produced and moved into circulation. Autacoids may thus have systemic effects by being transported via the circulation. These regulating molecules are also metabolized locally. In sum, these compounds typically are produced locally, act locally and are metabolized locally. Autacoids can have a variety of different biological actions, including modulating the activities of smooth muscles, glands, nerves, platelets and other tissue
Some autacoids are chiefly characterized by the effect they have on specific tissues, such as smooth muscle. With respect to vascular smooth muscle, there exist both vasoconstrictor and vasodilator autacoids. Vasodilator autacoids are released during periods of exercise. Their main effect is seen in the skin, where they facilitate heat loss.These are local hormones; they therefore have a paracrine effect. Some notable autacoids are: eicosanoids, angiotensin, neurotensin, NO (nitric oxide), kinins, histamine, serotonin, endothelins and palmitoylethanolamide.Autacoids, in the current model of physiology, are defined as locally produced and locally expressed factors that affect physiology. With this definition, there are numerous substances. However, in the context of integrative physiology according to the theory of Endobiogeny, we refer ANS autacoids without specification simply as “autacoids” because they are so fundamental to the theory of how the neuroendocrine system regulates the terrain, and to the origin of numerous disorders.