Question

Give an example(s) of a blood pressure-lowering hormone.

Answer 1

Hint: Some natriuretic peptide hormones are capable of controlling the extracellular fluid volume and blood pressure as well as contributing to other functions like a cardiac fraction, serum potassium balance, etc. These are produced in the walls of the heart.

Complete answer:
An example of blood pressure-lowering hormones is-
ANF or atrial natriuretic factor that reduces ECF volume by increasing renal sodium excretion and controls blood pressure.

Additional Information: Let us know more about this peptide hormone:
-Atrial natriuretic factor is a natriuretic peptide hormone mainly responsible for extracellular fluid volume control in our body.
-It is secreted from the cardiac muscle cells in the walls of the atria which contain volume receptors that can respond to an increased stretch of the wall due to an increase in arterial blood volume.
-The blood volume reduction carried out by this hormone results in a reduction of extracellular fluid volume as well as improvement in cardiac fraction, decrease in blood pressure, and increase in serum potassium.
-Structurally, it is a 28-amino acid peptide and in the middle, there's a 17-amino acid ring formed by a disulfide bond between two cysteine residues at the 7th and 23rd position is present.
-At the short arm of the chromosome, it is synthesized by the NPPA gene as an inactive preprohormone which later converts to the mature ANP on the cell surface by Stimulations such as stretching of the atrial wall, sympathetic stimulation, increases in sodium concentration, and vasoconstrictive effect of the endothelium.

Note: Another hormone that is similar to ANP is BNP or brain natriuretic peptide which is also secreted in the heart by the cardiac muscle cells of the ventricle. It has similar effects to ANP as well and works via the same receptors. The difference between these two is that the half-life of BNP is twice as long as that of ANP and hence are a better choice than ANP in the diagnosis of blood.