Comparative effects of angiotensin IV and two hemorphins on angiotensin-converting enzyme activity

Peptides. 2002 Aug;23(8):1465-70. doi: 10.1016/s0196-9781(02)00083-9.


The role of angiotensin IV (AngIV) in the regulation of angiotensin-converting enzyme (ACE) was studied in vitro. This study demonstrates that this active fragment appeared as a novel endogenous ACE inhibitor. Inhibitory kinetic studies revealed that AngIV acts as a purely competitive inhibitor with a K(i) value of 35 microM. AngIV was found to be quite resistant to ACE hydrolysis opposite to hemorphins which are both ACE inhibitors and substrates. In order to confirm a putative role of AngIV and hemorphins in the Renin-Angiotensin system (RAS) regulation, we studied their influence on AngI conversion. We noticed that 16.7 microM of both peptides decreased more than 50% of AngI conversion to AngII in vitro. The capacity of hemorphins, particularly LVVH-7, and AngIV to inhibit ACE activity here suggests a synergistic relation between these two peptides and the regulation of RAS.

Publication types

  • Comparative Study

MeSH terms

  • Angiotensin I / metabolism
  • Angiotensin II / analogs & derivatives*
  • Angiotensin II / pharmacology*
  • Animals
  • Hemoglobins / pharmacology*
  • Peptide Fragments / pharmacology*
  • Peptidyl-Dipeptidase A / drug effects*
  • Peptidyl-Dipeptidase A / metabolism
  • Rats


  • Hemoglobins
  • Peptide Fragments
  • Angiotensin II
  • hemorphin 7
  • angiotensin II, des-Asp(1)-des-Arg(2)-Ile(5)-
  • LVV-hemorphin-7
  • VV-hemorphin-7
  • Angiotensin I
  • Peptidyl-Dipeptidase A