Extraction of plasma prorenin by human heart.

Arterial plasma prorenin underwent 58% extraction during one passage through the coronary circulation in eleven patients undergoing myocardial metabolic studies. Active renin and renin substrate were unaffected. Changes in renin and renin substrate concentrations were not detected across the enterohepatic, femoral, or renal vascular beds. This high degree of selective extraction of prorenin by the heart accounts for its proposed half-life. Prorenin could be a cardiotropic hormone.