- In vivo measurement of coronary circulation angiotensin-converting enzyme activity in humans. Staniloae, C., Schwab, A.J., Simard, A., Gallo, R., Dyrda, I., Gosselin, G., Lesperance, J., Ryan, J.W., Dupuis, J. Am. J. Physiol. Heart Circ. Physiol. (2003)