Identification of telocytes in the porcine heart

Recently, a new interstitial cell type called telocyte has been identified. Telocytes are found in many organs including the heart, where they are especially well described. However, their presence in the porcine heart has not yet been proven. The pig is a valuable animal model in research because of its resemblance with man, making it interesting to determine whether telocytes can be found in pigs as well. The focus of this study is the identification and ultrastructural description of telocytes in the heart tissue of pig. Using transmission electron microscopy, telocytes were found in both left and right atrium and ventricle, usually close to cardiomyocytes and/or blood vessels. Their most important characteristic is the long cytoplasmic processes called telopodes, which have a moniliform aspect, measure tens of mu m and usually have a thickness below 0.2 mu m. This unique morphological feature enables telocytes to be recognized from other interstitial cells such as fibroblasts. Additional observations include the ability to release extracellular vesicles and to make contacts with other structures such as endothelial cells, suggesting a role in intercellular communication.