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Biomedical subjects

Y X Li

Publications and source records attributed to Y X Li.

3 recordsLinked to original sources
PubMed1992

[Use of a computer-controlled servo system to produce "ephysiological" contraction of isolated rat papillary muscle].

A computer-controlled servo system consisting of an ergometer with a force-displacement dual mode transducer, a Z-80 single-board microcomputer and a designed software was constructed. This servo system can be used to generate physiological contraction in isolated rat papillary muscle, in which the muscle went through a complete 4-phase cycle of force and length changes, similar to those undergone by muscle fibers in the beating heart during the cardiac cycle. This system is being used to investigate the tension-length relation and the network of isolated myocardium as well as the end-systolic tension-length relation and the force-velocity relation simultaneously.

Animals↗
PubMed1992

[Contraction stimulates incorporation of 3H-leucine and cell growth in cultured neonatal rat ventricular myocytes].

To determine whether contraction could influence cell growth, the rate of protein synthesis (3H-leucine incorporation) and cell diameter and volume were measured in cultured neonatal rat cardiac myocytes beating spontaneously or arrested by high potassium. In medium supplemented with 10% calf serum, the 3H-leucine incorporation for 24 h in contracting myocytes (CMC) was significantly higher by 14.2% than that in quiescent myocytes (QMC), i.e. 1,229 +/- 29 cpm/10(5) cells vs. 1,076 +/- 60 cpm/10(5) cells (P < 0.01, n = 5 for each group). The cell diameter and cell volume in QMC group were respectively 15.14 +/- 0.42 microns and 1,842 +/- 123 microns3, while in the CMC group the corresponding figures reached to 16.82 +/- 0.64 microns3 and 2,495 +/- 210 microns3, increased by 11.1% and 35.5% respectively (P < 0.01, n = 6 for each group). With prolongation of culture time, the differences in these parameters between CMC and QMC became even more significant. In all these experiments, there was no significant difference in cell number between the two groups (P > 0.05). It is concluded that contraction per se can accelerate protein synthesis and cell growth in neonatal rat ventricular myocardium.

Animals↗