Little Christopher was born three months prematurely, after only 25 weeks in his mother's womb. For now, he's resting comfortably in the nursery of Sainte-Justine Hospital. But when he opens his eyes, he could have serious problems with his sight, for the formation of blood vessels in the retina is not complete until after 40 weeks of pregnancy. From 50% to 80% of seriously premature infants are affected by a condition known as retinopathy of prematurity (ROP), leading, in the most serious cases, to total blindness.

"Curiously enough," says pediatrician Sylvain Chemtob, "despite the number of babies it affects and its impact throughout their lives, we know very little about this pathology."

As the first holder of a new Canada Research Chair for perinatal research in the faculty of medicine at the Université de Montréal, Dr. Chemtob has thrown light on the mechanisms of ROP over the past 10 years with the help of his team at Sainte-Justine Hospital. One of their breakthroughs involves two substances produced in large quantities in premature infants: prostaglandins and nitric oxide (NO). This disastrous duo forms a powerful relaxant that neutralizes the ability of blood vessels to contract. Even when just one of these substances is inhibited, the blood vessels regain their power to contract, and this allows better flow of blood to the retinas of premature babies. The researchers also discovered that the G protein-coupled receptors exist not only on the cell's plasma membrane but also in the nucleus. The finding contradicts biological dogmas in the field of lipids, and was recently mentioned in the prestigious review Science.

Using their expertise, Dr. Chemtob and his team have created a compound that is able to delay premature deliveries. The prostaglandins actually cause the muscle contractions of the uterus that are the initial phase of childbirth. By working on the G protein-coupled receptors, the compound succeeds in substantially lessening the rhythm of the contractions and so prolongs pregnancy. The compound (as well as the technology that made its development possible) was recently patented by Quebec-based Theratechnologies.

After studies in the United States, Dr. Chemtob joined the research team on fetal growth and development, which he heads today at Sainte-Justine Hospital. He is very proud of the work his group has done. "I'm convinced that we can become one of the finest perinatal teams in the world," he says. Above all, however, Sylvain Chemtob hopes to be able to treat babies born too early and even, eventually, prevent premature childbirth altogether.

Researcher: Sylvain Chemtob
Phone: (514) 345-4685
Funding: Theratechnologies