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.
[6] Blood concentration levels of prorenin are between 5 and 10 times higher than those of renin.
[2] There is evidence to suggest that, in diabetes mellitus, prorenin levels are even higher.
[2][7][8] One study using relatively newer technology found that blood concentrations levels may be several order of magnitude higher than previously believed, and placing it at micrograms rather than nanograms per millilitre.
[9] Prorenin occurs in very high concentrations in amniotic fluid and amnion.