Abstract:Objective To observe the expression of calcium-dependent proline-rich tyrosine kinase-2（Pyk2） in myocardium of rheumatic heart disease, the relationship between its role and cardiac fibrosis and clinical significance. Methods The blue myocardium collagen stain were analysed after Masson staining in 30 patients with rheumatic heart disease （RHD group） and 6 normal myocardium specimens （control group）. The contents of hyaluronic acid （HA）, laminin（LN） and type IV collagen（IV-C） were detected by radio-immunity method,and the expressions of Pyk2 protein and messenger ribonucleic acid（mRNA） were explored by immunohistochemistry methods and reverse transcriptase polymerase chain reaction （RT PCR）,then the correlations of these results were statistically analyzed. Results The contents of HA,LN and IV C in RHDgroup increased compared to control group（174.95±76.14μg/L vs. 70.06±15.63μg/L, 153. 86 ± 20. 72μg/L vs. 90.01±14. 11μg/L, 95. 26±7.66μg/L vs. 63. 21±10.62μg/L; P= 0.003, 0. 013, 0. 035）. The Pyk2 absorption and the ratio of Pyk2 mRNA/glyceraldehyde phosphate dehydrogenase （GAPDH） in RHD group were significantly higher than those in control group （0. 325 ± 0. 032 vs. 0.106±0.013, 0.870±0.085 vs. 0.573±0.042; P=0.048, 0.006）.There were positive correlativity between the expression of Pyk2 protein and HA, LN and IV-C （r=0. 611, 0. 743, 0. 829, P〈0. 01）, there were positive correlativity between the expression of Pyk2 mRNA and LN, IV-C （r=0. 794, 0. 766, P〈0.05）. Conclusion Pyk2 may play a key role in the proceeding of cardiac fibrosis in rheumatic heart disease by increasing collagen synthesis in myocardium.