Figure 1: Effects of infrasound on the proliferation and collagen synthesis of cultured cardiac fibroblasts stimulated by angiotensin II. Quiescent cells were stimulated with Ang II (1 μmol/L) or in the control conditions for 1, 2, and 3 days with or without exposure to infrasound (4–20 Hz, 79.75–86.11 dB) for 2 h a day followed by the assessment of [³H] thymidine incorporation (a) or [³H] proline incorporation (b). The results were presented as times of control. The data were from four independent experiments with each assay in triplicate. ^*P < 0.05, ^**P < 0.01 versus control group; ^##P < 0.01 versus Ang II group