APJ's Yin-Yang Role in Cardiac Function (image) Sanford-Burnham Medical Research Institute Caption APJ's yin-yang role in cardiac function: the receptor APJ serves a dual function in heart health, depending on how it's activated. While APJ enhances heart health upon binding the hormone apelin (green), APJ can also trigger heart enlargement and failure when it senses certain mechanical changes (red). Credit Sanford-Burnham Medical Research Institute Usage Restrictions Free to use in conjunction with stories about this study only, using provided caption and credit. Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.