419XI Yu-Tao et al: Centrifugal Force Stretcher a New of in vitro Mechanical Cell Stimulator Received 2003-07-14 Accepted 2004-03-18

Abstract: A number of mechanical cell stimulators have been used to study the effect of mechanical stimulation on cells in vitro. But the efficiency of these devices is not fully desirable. We recently developed a new device for mechanical cell stimulation, the centrifugal force stretcher, and compared its efficacy with that of the traditional Flexercell Strain Unit. When the mechanical stretcher circumrotates with certain speed, cardiac myocytes attached on the plate are stretched and elongated by centrifugal force. Neonatal rat cardiac myocytes were isolated by enzymatic dissociation from the hearts of 3~5 d old Sprague Dawley rats, and were mechanically stimulated by traditional 20% stretch and 180 r/min centrifugal force for 12 and 24 h. The effects of mechanical stimulation on the hypertrophic response of neonatal rat cardiac myocytes and production of angiotensin (Ang ) were examined. Compared with the non-stretch group, the radioactivity of 3H-leucine incorporated into the stretch-stimulated cardiac myocytes in the centrifugal force stretch group was significantly higher [(1295.1