Angiotensin-(1-12) [Ang-(1-12)] functions as an endogenous substrate for the productions of Ang II and Ang-(1-7) by a non-renin dependent mechanism. This study evaluated whether Ang-(1-12) is incorporated by neonatal cardiac myocytes and the enzymatic pathways of ¹²?I-Ang-(1-12) metabolism in the cardiac myocyte medium from WKY and SHR rats.