Then, the researchers induced DVTs in the three groups of mice in the heparin experiment. The mice that received LMWH before the DVT formed had the fastest endothelial repair, followed by those that received LMWH soon after the DVT was induced. The biggest difference was seen at four days after the DVT formed, but by day 14 the two heparin-treated groups of mice had about the same extent of repair. The pre-treated mice had the greatest recovery of the vein wall lining.
Using real-time polymerase chain reaction tests, the researchers were also able to look at patterns of gene expression in harvested veins in culture. As with the cell staining, they saw signs that the pre-treated mice reacted in a way that suggested fastest recovery.
While the new results cant immediately be translated into human patients, they do help illuminate the process by which LMWH works including the advantages of pre-treatment in at-risk patients, or early treatment of patients in whom a DVT has formed.
Hospitalized patients who are on prophylactic heparin can still develop clots, but these results suggest that having heparin on board can lessen the long-term impact of a DVT, says Henke. At the same time, our findings also suggest that rapid heparin treatment after a DVT forms is important for long-term healing. This conclusion is supported by a previous U-M study, published in Thrombosis and Haemostasis in 2007, showing that the longer a clot is in contact with a vein, the worse the damage.
Now, the team is studying the proteins in the vein wall that are involved in promoting endothelial health and regeneration after an injury or other insult. Theyre also working on the clinical level to increase the appropriate use of preventive measures among
|Contact: Kara Gavin|
University of Michigan Health System