Sorry, you need to enable JavaScript to visit this website.
Blood vs. Drugs
Safety Assessment
Mary Parker

Blood vs. Drugs

Delving into how pharmaceuticals may adversely affect coagulation. A Charles River sabbatical story.

Florence Poitout, Scientific Director of Clinical Pathology at Charles River Labs in Senneville, QC, recently spent a month-long sabbatical working on a sticky issue. One of the most common side effects of pharmaceuticals is platelet dysfunction, which affects blood's ability to clot. This can have dangerous consequences for patients, and must be considered during drug development.

"In the recent years, there has been a large demand for in vitro or in vivo platelet aggregation studies," said Poitout. "Sponsors want to know if their new compound might influence platelet aggregation by increasing it or decreasing it. For that, we offer in vitro platelet  assays on human blood, but I am constantly looking for new methods in order to detect the early influence of compounds on platelets and coagulation factors."

In order to better her understanding of platelets, especially the enzyme thrombin that controls blood clotting, Poitout spent her sabbatical at several labs working in thrombosis and hemostasis to learn their assay processes. These visits not only refined her lab skills, but also allowed her to form relationships at labs that may someday collaborate with CRL.

Poitout spent one week each with Dr. Barry S. Coller at Rockefeller University Hospital in New York City, with Dr. Laurence Camoin-Jau at Centre Hospitalier de la Timone in Marseille, France, and with Dr. Christian Bédard of the University of Montréal. She also visited Dr. Yahe Merhi, at the Institute of Cardiology of the University of Montréal.

Poitout warns that her sabbatical excursion was more difficult to organize than expected, though the rewards of her efforts have already been seen at her home lab. She brought back experience with platelet aggregation assays on mice that she has already implemented at CRL, and is working on a book chapter. The knowledge gained by her travels will have enormous impact on the daily work of her lab.

"Platelets are not so well understood, and compound toxicity on platelets is quite difficult to manage," she said. "This is a very important subject and we have to deal with it every day."


Charles River is committed to providing its employees with opportunities for growth. To learn how you can join the team, visit Also, read more stories about Charles River’s sabbaticals.