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Figure 1. Effect of TAPs on cell growth in cultured human fibroblasts. A) Cells (105) were plated and supplied with complete medium (10% BS) or serum-free media or were serum-free (–). Where indicated, a 1 cm2 aliquot of TAPs (TAPs 1=1.0x109; TAPs 2=0.75x109; TAPs 3=0.5x109; TAPs 4=0.2x109), obtained as described in Materials and Methods, has been added to the serum-free medium. At the indicated times, the cells were trypsinized and counted. Data represent mean ± SD of six independent experiments in duplicate. B) Alternatively, equal amounts of cells were placed in serum-free media (–) and were supplied with thrombin-treated platelet-poor plasma (T-PPP), thrombin-activated platelets (TAPs; 1.0x109), 10% human serum and thrombin (T; 0.5 NIH U), as indicated. At the indicated times, the cells were trypsinized and counted. Data represent means ± SD of three independent experiments in duplicate. C) Six-well plates were seeded with 105 cells/plate in 1 ml complete medium. After incubation for 24 h at 37°C, the medium was removed and replaced with Dulbecco’s modified Eagle medium (DMEM) containing 0.25% BSA and no serum. After an additional 24 h, the medium was removed again and replaced with complete DMEM, or DMEM 0.25% albumin with or without TAPs. Incubation was prolonged for additional 16 h, and the incubation media replaced with the same media supplemented with [3H]thymidine (500 nCi/ml). After 1 h, media were removed and thymidine incorporation was measured as described in Materials and Methods. The bar graph represents means ± SD of three independent experiments in triplicate.
