Superoxide anions mediate proliferative response in cardiac fibroblasts

The study was undertaken to examine whether superoxide anions mediate a pro liferative response in cardiac fibroblasts. Cardiac fibroblasts isolated fr om newborn Wistar rats were exposed to superoxide anion generating system ( hypoxanthine + xanthine oxidase) and its effect on cell growth was assessed . A stimulatory response on fibroblast proliferation was observed. The prop ortion of proliferating cells increased within 3 h of treatment compared to the control and the cell density after 96 h of exposure remained significa ntly high (P<0.0005). Inclusion of antioxidants neutralised the stimulatory response, fortifying the role of superoxide anions in cell proliferation. This observation indicates that superoxide anions can mediate a fibrotic re action in the cardiac tissue.