Endogenous plasma adrenaline concentrations in resting adults usually are less than 10 ng/L, but they may increase by 10-fold during exercise and by 50-fold or more during times of stress. Pheochromocytoma patients often have plasma adrenaline levels of 1000–10,000 ng/L. Parenteral administration of adrenaline to acute-care cardiac patients can produce plasma concentrations of 10,000 to 100,000 ng/L. Biosynthesis
In chemical terms, adrenaline is one of a group of monoamines called the catecholamines. Adrenaline is synthesized in the chromaffin cells of the adrenal glands adrenal medulla and a small number of neurons in the medulla oblongata in the brain through a metabolic pathway that converts the amino acids phenylalanine and tyrosine into a series of metabolic intermediates and, ultimately, adrenaline. Tyrosine is first oxidized to L-DOPA by tyrosine hydroxylase; this is the rate-limiting step. Then it is subsequently decarboxylated to give dopamine by DOPA decarboxylase (aromatic L-amino acid decarboxylase). Dopamine is then converted to noradrenaline by dopamine beta-hydroxylase, which utilizes ascorbic acid (vitamin C) and copper. The final step in adrenaline biosynthesis is the methylation of the primary amine of noradrenaline. This reaction is catalyzed by the enzyme phenylethanolamine N-methyltransferase (PNMT), which utilizes S-adenosyl methionine (SAMe) as the methyl donor. While PNMT is found primarily in the cytosol of the endocrine cells of the adrenal medulla (also known as chromaffin cells), it has been detected at low levels in both the heart and brain. Regulation
The major physiologic triggers of adrenaline release center upon stresses, such as physical threat, excitement, noise, bright lights, and high or low ambient temperature.
This list of autoimmune diseases is categorized by organ and tissue type to help locate diseases that may be similar. Autoimmune diseases qualifiers
Overview of the qualifiers for the list. Autoimmune diseases
Major organs
Glands
Digestive system
Tissue
Autoimmune comorbidities
This list includes conditions that are not diseases but signs common to autoimmune disease. Some, such as chronic fatigue syndrome, are controversial. These conditions are included here because they are frequently listed as autoimmune diseases but should not be included in the list above until there is more consistent evidence. Non-autoimmune
At this time, there is not sufficient evidence—direct, indirect, or circumstantial—to indicate that these diseases are caused by autoimmunity. These conditions are included here because:

The disease was listed in the prior version of this table
The disease is included in several widely used lists of autoimmune disease and is shown here to ensure that a person visiting this page does not conclude that the disease was not considered. Before moving a condition from here to the list of autoimmune diseases, references should be provided in the Wikipedia page for the condition that point to evidence, direct or indirect, that it is an autoimmune disease. See also
Autoimmune Autonomic Ganglionopathy (AAG)


== References ==