| Abstract: | An experimental model has been devised to permit morphologic and metabolic characterization of cells subjected to a range of cyclic mechanical stimuli similar to those which may prevail in blood vessel walls. A unique feature is the use of purified elastin membranes prepared from bovine aortas as extensible substrates for cell growth. Cells attached firmly to such membranes which could then be subjected to continuous stretching and relaxation or displacement without stretching by a motor coupled to a movable supporting frame. Various combinations of frequencies, amplitudes and rates of deformation have been used over extended periods with minimal fatigue or disruption of the elastin substrate. The effects of cyclic stretching on 14C]proline incorporation into protein and collagen and 3H]thymidine incorporation into DNA by rabbit aortic smooth muscle cells were distinct from those attributable to agitation without stretching, indicating that cells responded differently to these modes of stimulation. Increases in rate of protein or DNA synthesis induced by stretching were just as marked after 48 h of stimulation as they were at the outset of an experimental period. Since the system permits observations of cell response to independently variable components of pulsatile stress over extended periods and under a variety of culture conditions, it may be expected to provide new data concerning the interaction of mechanical with hormonal and genetic factors in the elaboration of connective tissue components. |
