Catestatin

Where it comes from

Made in

Chromaffin cells of the adrenal medulla and sympathetic nerve endings, released with catecholamines

Sent out by

With adrenaline and noradrenaline, as a brake on their own release

Acts on

• Chromaffin cells
• Sympathetic nerve terminals
• Heart
• Vessels (histamine release from mast cells)

What it does

• Shuts off catecholamine release, a negative feedback on the cells that made it ¹
• Lowers blood pressure and slows the heart
• Kills bacteria and fungi in the laboratory

In medicine

• Catestatin is already low in the still-healthy children of people with hypertension, and the Gly364Ser variant changes autonomic function and lowers diastolic pressure by about 5 to 6 mmHg ²
• No approved test and no medicine. Chromogranin A, the protein it comes from, is measured as a neuroendocrine tumour marker, and that result says nothing about catestatin
• Measuring it is the hard part. It is one cut piece of a storage protein that is chopped into many fragments, and the antibodies in use differ in which fragments they see, so published concentrations differ by more than the diseases do ³

Beyond the body’s own use

• A fragment of a storage protein is not a hormone with a gene of its own. Chromogranin A packages catecholamines inside the granule, and catestatin is one of the pieces left when that package is processed, so how much exists is a question about processing rather than about CHGA expression ¹
• It is studied as a marker in heart failure, where plasma concentrations predicted death or unplanned admission over two years in a 52-patient cohort; nothing of the kind is in clinical use ³
• It lowers blood pressure in hypertensive rats and kills microbes in a dish. No human trial has been registered, and the measurement problem above is why one would be hard to design ²