Regulation of cardiovascular collagen synthesis by mechanical load.

1. Introduction the mechanical environment an extremely fascinating area of study. The cardiovascular system is constantly exposed to Research into the role of mechanical force in tissue mechanical perturbation from shear and tensile stresses. growth has been advanced considerably over the last 10 During development cardiovascular cells respond to years or so with the development of devices designed to changes in mechanical load; growing, dividing and laying subject isolated cells to a variety of mechanical loads down extracellular matrix. Changes in the normal levels of including shear stress, mechanical strain, tension and these forces then have further profound effects on these compression. These systems have enabled us to explore the cells resulting in abnormal changes in cardiovascular direct effects of defined forces on the function of specific structure and consequently function. These remodelling cell types including cells of the cardiovascular system, processes suggest that the mechanical environment is a key bone, tendon, lung and skeletal muscle in the absence of modulator of cell function. humoral, neuronal or nutritional regulation. The importance of mechanical forces in the regulation of The aim of this review is to outline physiological and tissue growth, development and disease has been ap-pathological situations in which mechanical forces have an preciated for many years. Early studies in the 1960–70s impact on cardiovascular extracellular matrix composition demonstrated, for example, the importance of mechanical – the extracellular matrix being important in determining load in skeletal muscle growth and development. It was the structure and function of the cardiovascular system. In determined that even in the presence of adequate nutrition, vitro studies that support the concept that mechanical and with hormonal and neuronal control, skeletal muscle forces directly influence cell function will be described would not grow without mechanical stimulation [1–3]. The including the advances being made in the elucidation of reverse is also true – disuse of a skeletal muscle leads to the pathways of mechano-signal transduction. Interaction atrophy [4]. Similarly bone growth and remodelling is between growth factors, extracellular matrix and mechani-dependent on continuous stimuli of pressure and tension cal load, in terms of the mechano-transduction process, [5]. Growth of the lung is also partly regulated by will be highlighted specifically. Readers interested in the mechanical forces [6]. The response of the cardiovascular regulation of myocyte growth by mechanical load are system to mechanical stimuli is therefore not unique, directed to other review articles [7,8]. This subject will …