Angiotensin converting enzyme 2 (ACE2) activity in fetal calf serum: implications for cell culture research

Cell culture experiments often employ the use of culture media that contain fetal calf serum (FCS). The angiotensin peptides angiotensin II and angiotensin 1–7 have opposing effects with angiotensin converting enzyme 2 (ACE2) being the enzyme predominantly responsible for generating angiotensin 1–7 from angiotensin II. The effect of FCS on angiotensin peptides has not previously been described. We have shown that FCS has ACE2 enzyme activity capable of degrading angiotensin II and generating angiotensin 1–7. Researchers should be aware that FCS possesses ACE2 activity and that heat-treating FCS to 56 °C only partially inhibits this enzyme activity, whereas heat-treating to 70 °C completely abolishes ACE2 activity.