Prorenin
Prorenin (/prəˈriːnɪn/[1]) is a protein that constitutes a precursor for renin,[2] the hormone that activates the renin–angiotensin system, which serves to raise blood pressure. Prorenin is converted into renin by the juxtaglomerular cells, which are specialised smooth muscle cells present mainly in the afferent, but also the efferent, arterioles of the glomerular capillary bed.
Prorenin is a relatively large molecule, weighing approximately 46
History
Prorenin was discovered by Eugenie Lumbers[4] in 1971.[5]
Synthesis
In addition to juxtaglomerular cells, prorenin is also synthesised by other organs, such as the adrenal glands, the ovaries, the testis and the pituitary gland, which is why it is found in the plasma of anephric individuals.[6]
Concentration
Blood concentration levels of prorenin are between 5 and 10 times higher than those of renin.
Pregnancy
Prorenin occurs in very high concentrations in amniotic fluid and amnion.[3] It is secreted in large amounts from the placenta and womb, and from the ovaries.[10]
Conversion to renin
Proprotein convertase 1 converts prorenin into renin,[11] but proprotein convertase 2 does not.[12]
There is no evidence that prorenin can be converted into renin in the circulation. Therefore, the granular (JG) cells seem to be the only source of active renin.[13]
References
- ^ "Renin | Definition of Renin by Lexico". Lexico Dictionaries | English. Archived from the original on November 9, 2019.
- ^ PMID 16585418.
- ^ PMID 25902786.
- S2CID 44555887.
- PMID 4105386.
- PMID 18322669.
- S2CID 102634216.
- PMID 17259648.
- S2CID 231859379.
- S2CID 229294165.
- ^ "EC 3.4.21.93". www.qmul.ac.uk.
- ^ "EC 3.4.21.94". www.qmul.ac.uk.
- ISBN 978-1-4614-3784-0.