Calcium-phosphate bions do specifically induce hypertrophy of damaged intima in rats

Aim. To evaluate specificity of endothelial toxicity of calcium-phosphate bions (CPB) in vivo. Material and methods. Toxicity of calcium-phosphate bions and magnesiumphosphate bions (MPB) in relation to intima of abdominal aorta of the Wistar rats, was assessed by single intravenous injection after balloon angioplastics with further explanting of aortas in five weeks. Bioptates were analyzed: 1) with classical histological methods (hematoxilin-eosine, alizarin red, van Gison, Russell-Movat) with light microscopy; 2) immune fluorescence coloring of cryoslices (combinational coloring for marker of mature endothelial cells CD31 and marker of progenitory CD34, for CD31 and marker of vascular smooth muscle cells α-smoothmuscle actin (α-SMA), for vimentin and α-SMA, for extracellular matrix marker collagen type IV and α-SMA, after all colorings there was additional nuclear 4’,6-diamidine-2-phenylindol color) with further confocal microscopy. In all animals the blood was collected with serum extraction for systemic inflammation molecules analysis, as chemoattractant protein (МСР-1/CCL2) and ceruloplasmin via the immune enzyme analysis. Results. With the difference from CPB, MPB did not lead to intimal hypertrophy in abdominal aorta in rats. Shaping of neointima in aorta is related with CPB-induced endothelium damage that induces a phenotype shift in mesenchymal cells (smooth muscle cells and fibroblasts) from contractile (for smooth muscle) and non-active (for fibroblasts) towards synthetizing. Conclusion. Intravenous load of MPB did not lead to intimal hypertrophy that witness on specificity of endothelial toxicity of CPB, with phenotypical shift of the mesenchymal cells in neointima.