Xi Yu-Tao, Bai Xiao-Jun, Wu Ge-Ru, Ma Ai-Qun
Department of Cardiology, the First Hospital, Key Laboratory of Environment and Genes Related to Diseases of Ministry of Education, Xi'an Jiaotong University, Xi'an 710061, China.
Sheng Li Xue Bao. 2004 Jun 25;56(3):419-23.
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 II (Ang II) were examined. Compared with the non-stretch group, the radioactivity of (3)H-leucine incorporated into the stretch-stimulated cardiac myocytes in the centrifugal force stretch group was significantly higher [(1295.17+/-51.19) vs (1122.67+/-51.63) in 12 h; (1447.5+/-35.96) vs (1210.67+/-90.92) in 24 h, P<0.05]. Ang II was also dramatically increased by 128% in 12 h (P<0.05) and 139% in 24 h (P<0.01). After the myocytes was stretched for 24 h, the LDH level in the medium in the Flexercell Strain Unit group was significantly higher than that in the centrifugal force group [(14.5+/-8.7) U/L vs (7.8+/-4.3) U/L, P<0.05]. The centrifugal force stretcher is a new and improved mechanical cell stimulator with the same effects on the protein synthesis and Ang II secretion of the cardiac myocytes, and the damage to the cells bronght by this stimulator is relatively slighter in comparison with the Flexercell Strain Unit.
许多机械细胞刺激器已被用于体外研究机械刺激对细胞的影响。但这些装置的效率并不完全理想。我们最近开发了一种用于机械细胞刺激的新装置——离心力拉伸器，并将其功效与传统的Flexercell应变装置进行了比较。当机械拉伸器以一定速度旋转时，附着在平板上的心肌细胞会因离心力而被拉伸和拉长。新生大鼠心肌细胞通过酶解从3至5日龄的Sprague Dawley大鼠心脏中分离出来，并分别用传统的20%拉伸和180转/分钟的离心力进行12小时和24小时的机械刺激。检测了机械刺激对新生大鼠心肌细胞肥大反应和血管紧张素II（Ang II）产生的影响。与未拉伸组相比，离心力拉伸组中拉伸刺激的心肌细胞掺入的（3）H-亮氨酸放射性显著更高[12小时时为（1295.17±51.19）对（1122.67±51.63）；24小时时为（1447.5±35.96）对（1210.67±90.92），P<0.05]。Ang II在12小时时也显著增加了128%（P<0.05），在24小时时增加了139%（P<0.01）。细胞拉伸24小时后，Flexercell应变装置组培养基中的乳酸脱氢酶（LDH）水平显著高于离心力组[（14.5±8.7）U/L对（7.8±4.3）U/L，P<0.05]。离心力拉伸器是一种新型且改进的机械细胞刺激器，对心肌细胞的蛋白质合成和Ang II分泌具有相同的作用，并且与Flexercell应变装置相比，该刺激器对细胞造成的损伤相对较小。
