Myofibroblasts and local angiotensin II in rat cardiac tissue repair

Tissue repair is a fundamental property of vascularized tissue. At sites of injury, phenotypically transformed fibroblast-like cells are responsible for fibrous tissue formation, expressed principally as type I and III fibrillar collagens. These cells are termed myofibroblasts because they contain alpha-smooth muscle actin microfilaments and are contractile. In vivo studies of injured rat cardiac tissues and in vitro cell culture studies have shown that such fibroblast-like cells contain requisite components for angiotensin peptide generation and angiotensin II receptors. Such locally generated angiotensin II acts in an autocrine/paracrine manner to regulate collagen turnover and thereby tissue homeostasis in injured tissue. (C) 1997 published by Elsevier Science Ltd.