Expression of Platelet Membrane Glycoprotein Ib/Ⅸ/Ⅴ Complex,a Receptor of Thrombin,in Patients with Hemorrhagic Thrombopathy

To investigate the role of platelet membrane glycoprotein （GP） Ib/Ⅸ/Ⅴ complex and its subunit GP Ibα in patients with hemorrhagic thrombopathy （HT）, the expressions of GP Ib/Ⅸ/Ⅴ complex and GP Ibα,defined as mean fluorescence intensity （MFI）, were assessed by flow cytometry. The maximum aggregation of platelet was determined by turbidity method. These indicators were compared among 68 HT patients with the presenting complaint of hemorrhage, 33 well-controlled HT patients and 32 normal healthy subjects. The results showed that the MFI of GP Ib/Ⅸ /Ⅴ complex and GP Ibα was markedly lower in HT patients with current hemorrhage than that in the healthy subjects, with difference being statistically significant （P〈0.05）. There was no significant difference in the expressions of GP Ib/ Ⅸ/ Ⅴ complex and GP Ibα between well-controlled HT patients and normal healthy subjects （P〉0.05）. It was concluded that the expression of GP Ib/Ⅸ /Ⅴ complex, the receptor of thrombin and von Willebrand factor, was down-regulated in HT patients with current hemorrhage, which might result in the dysfunction of platelet aggregation and recurrence of HT.

Expression of platelet membrane glycoprotein Ib/IX/V complex,a receptor of thrombin,in patients with hemorrhagic thrombopathy

Summary To investigate whether peroxisome proliferators-activated receptor-γ (PPARγ) ligand Troglitazone can reduce endothelial injury and activation during storage of harvested saphenous vein grafts. Segments of human saphenous vein graft were collected from 9 patients undergoing coronary bypass surgery and then divided into two equal parts of control and test specimens, were stored in either heparinized blood (control group) or heparinized blood containing 20 μmol/L troglitazone (test group) for 1 h at room temperature. Tissue distribution and protein expression of VCAM-1, ICAM-1, and endothelial nitric oxide synthase (eNOS) were compared using immunohistochemistry and Western blot analysis. Myeloperoxidase (MPO) activity, a marker of neutrophil sequestration in human saphenous vein grafts, was also measured in each group. The expression of ICAM-1 (753±132 versus 7201±934; P<0.01), VCAM-1 (3731±294 versus 8292±793; P<0.01), and MPO activity (1.52±0.42 U/g, 5.04±1.26 U/g P<0.01) were significantly lower in test group. In contract, eNOS expression (7983±834 versus 3989±1008; P<0.01) was significantly higher in test group. PPARγ ligand troglitazone might reduce endothelial injury during the storage period of human saphenous vein grafts. The project was supported by a grant from the Health Ministry of Hubei Province (JX2B16).