Upregulation of tissue‐type plasminogen activator in inflamed human dental pulps

Aim  To compare tissue‐type plasminogen activator (t‐PA) expression in normal human pulp and inflamed human pulp tissue specimens. Methodology  Thirty pulpal tissue specimens (13 normal and 17 inflamed pulps) were obtained from extracted third molars. The levels of t‐PA between normal pulp and inflamed pulp tissues were compared using the quantitative reverse‐transcriptase polymerase chain reaction analysis. In addition, immunohistochemistry was used to identify the in situ localization of t‐PA expression in pulp specimens. Wilcoxon–Mann–Whitney rank sum test was applied for the statistical analysis of the results. Results  t‐PA mRNA gene was found more in inflamed pulps when compared with normal pulp tissue ( P  < 0.05). The results from immunohistochemistry demonstrated that t‐PA expression was significantly higher in the inflamed pulp ( P  = 0.025). t‐PA stain was detected in the fibroblasts, inflammatory infiltrates and endothelial cells. Conclusions  t‐PA expression was significantly higher in inflamed pulp tissue. t‐PA may play an important role in the pathogenesis of pulpal inflammation.