Increased<unk>  secretion is observed in pheochromocytoma, hypoglycemia, myocardial infarction and to a lesser degree in essential tremor (also known as benign, familial or idiopathic tremor). A general increase in sympathetic neural activity is usually accompanied by increased<unk>  secretion, but there is selectivity during hypoxia and hypoglycaemia, when the ratio of<unk>  to noradrenaline is considerably increased. Therefore, there must be some autonomy of the adrenal medulla from the rest of the sympathetic system. Myocardial infarction is associated with high levels of circulating<unk>  and noradrenaline, particularly in cardiogenic shock. Benign familial tremor (BFT) is responsive to peripheral β adrenergic blockers and β2-stimulation is known to cause tremor. Patients with BFT were found to have increased plasma<unk> , but not noradrenaline. Low, or absent, concentrations of<unk>  can be seen in autonomic neuropathy or following adrenalectomy. Failure of the adrenal cortex, as with Addison's disease, can suppress<unk>  secretion as the activity of the synthesing enzyme, phenylethanolamine-N-methyltransferase, depends on the high concentration of cortisol that drains from the cortex to the medulla.
Adrenaline
Synephrine
Norepinephrine
Norepinephrine 
Adrenomedullin
Dobutamine
Dopamine
Dopamine 