收缩活动促进新生大鼠培养心室肌细胞的~3H-亮氨酸掺入和细胞生长

CONTRACTION STIMULATES INCORPORATION OF ~3H-LEUCINE AND CELL GROWTH IN CULTURED NEONATAL RAT VENTRICULAR MYOCYTES

本工作应用培养的新生大鼠心室肌细胞,以~3H-亮氨酸掺入、细胞直径和细胞体积为指标,观察了收缩活动对心肌蛋白质合成速率及细胞生长的影响。在含10％血清的培养介质中,常钾搏动组的心肌细胞(CMC)的~3H-亮氨酸掺入显著高于高钾停搏组的心肌细胞(QMC),24h的掺入量分别为1229±29与1076±60cpm/10~5细胞(每组n=5,P<0.01),CMC掺入为QMC的114.2％。QMC组细胞直径和体积分别为15.14±0.42μm和1842±123μm^3,而CMC组为16.82±0.64μm和2495±210μm^3,分别比前者高11.1％和35.5％(P<0.01,每组n=6)。这些变化随培养时间的延长更趋明显,但两组间的细胞数目并无显著差异(P>0.05)。上述结果表明:收缩活动本身能促进心肌细胞蛋白质合成和细胞生长。

To determine whether contraction oould influence cell growth, the rate ofprotein synthesis (~3H-leucine incorporation) and cell diameter and volume weremeasured in cultured neonatal rat cardiac myocytes beating spontaneously orarrested by high potassium. In medium supplemented with 10% calf serum, the^3H-leucine incorporation for 24 h in contracting myocytes (CMC) was signifi-cantly higher by 14.2% than that in quiescent myocytes (QMC), i.e. 1 229±29cpm/10~5 cells vs. 1 076±60 cpm/10~5 cells (P<0.01, n=5 for each group). Thecell diameter and cell volume in QMC group were respectively 15.14±0.42 μmand 1 842±123 μm^3, while in the CMC group the corresponding figures reachedto 16.82±0.64 μm^3 and 2 495±210 μm^3, increascd by 11.1% and 35.5% res-pectively (P<0.01, n=6 for each group). With prolongation of culture time, thedifferences in these parameters between CMC and QMC became even more signi-ficant. In all these experiments, there was no significant difference in cell num-ber between the two groups (P>0.05). It is concluded that contraction per secan accelerate protein synthesis and cell growth in neonatal rat ventricularmyocardium.