A new vacuum-operated stress-providing instrument that applies static or variable duration cyclic tension or compression to cells in vitro.

An instrument providing cyclic stress to cells cultured in vitro has been developed. The unit uses a vacuum to deform a plastic Petri dish yielding 0.13% compression to cells on the inner surface, measured by strain gauge recordings. A regimen of 25 s stress and 5 min relaxation induced no significant change in synthesis of a 45 X 10(3) Mr protein that comigrates with actin, whereas a 52 X 10(3) Mr protein that comigrated with tubulin decreased from 12.7 +/- 0.451% of the total protein synthesized in control, static cells to 8.53 +/- 0.182% in stressed cells. The unit may have a broad application in monitoring biochemical changes in response to stress in cells such as muscle, lung, tendon, ligament and bone that are normally subjected to tension or compression.