Cyclic mechanical stretch induces VEGF secretion in primary ARCMs.

<p><b>A</b>) Cyclic mechanical stretch for either 24 h or 48 h induces a significant increase in VEGF secretion in primary ARCMs attached to laminin compared to non-stretched controls. Stretched (10% stretch) and non-stretched control (0% stretch) cells were allowed to adhere to laminin for 24 h prior to initiating experiments. VEGF concentration in the conditioned media of non-stretched and stretched ARCMs was analyzed by ELISA. ***<i>P</i><0.001; One-Way ANOVA with a Bonferroni post-test was used to determine the statistical significance of data. The values represent the average of three independent experiments. <b>B</b>) Isolated ARCMs remain viable in culture when attached to laminin. Cell cultures were examined for their ability to reduce MTT after 24 h or 48 h in culture. Fold induction in relative mitochondrial activity represents the amount of viable cells at each time point. ***<i>P</i><0.001; One-Way ANOVA with a Bonferroni post-test was used to determine the statistical significance of data. <b>Insert:</b> The isolation procedure yielded a >90% pure ARCM population. Phase contrast image of isolated, primary ARCMs 24 h after binding to laminin demonstrate that ARCM differentiated morphology is maintained as indicated by the rod-shaped, branched striated cell examined at 40X magnification.