Steve Milloy wrote an excellent opinion piece for Fox News today (Animal Rights, Research Wrongs) attacking People for the Ethical Treatment of Animals and other animal rights groups. One of the groups Milloy defends is the March of Dimes. Since animal rights groups claim animal research into birth defects has done nothing but waste money, lets take a look at the lies of an animal rights group, Physicians Committee for Responsible Medicine, and compare it to the reality of what the research community has accomplished.
Milloy notes that the March of Dimes 2001 National Ambassador is a six year old boy who is alive today because of lung surfactant therapy. Lung surfactant therapy was developed thanks to animal research that the March of Dimes helped sponsor. Briefly, when you breathe your lungs contract. Lung surfactant is the substance that makes them expand again. Many infants born prematurely do not produce enough lung surfactant, and as a result their lungs tend to collapse which leads to increased mortality.
PCRM has a different take on the role of animal research and the March of Dimes in finding an effective treatment for lung surfactant deficiency. On the CharitiesInfo.Org web site, PCRM claims,
8. Did surfactant therapy for premature infants depend on animal experiments as the March of Dimes claims?
No. Surfactant is a natural compound that allows the lungs to operate normally. It was discovered in experiments using animal and human lung specimens in the late 1950s. Although some animal lung specimens were used, human lung specimens could have been used alone. Three years after its discovery, researchers demonstrated that premature infants have no surfactant in their lungs, but that the substance is present in the lungs of more mature infants, children, and adults. Within a few years, trials had begun administering this substance to infants with lung problems. Human studies continue today to improve surfactant therapy for infants.
As with most animal rights lies there is a grain of truth to this account, but if human studies were all that was needed to create lung surfactant therapy, it is a bit odd that the most effective such therapy is made from the lungs of calves. Here’s the reality.
In the mid-1950s a Boston-area physiologist, John Clements, discovered lung surfactant. He soon figured out that the substance’s function was to prevent lung collapse. A few years later in 1959, Mary Ellen Avery, a Boston-area pediatrician, discovered that premature infants born with a disorder called Hyaline Membrane Disease lacked lung surfactant which was the reason their lungs were collapsing.
Now if you take the PCRM account at face value, that settles it. Lung surfactant was discovered, and researchers knew that surfactant deficiency was the major cause of lung collapse in premature infants. So it was just a simple matter of developing a treatment and applying it to babies, right? Not by a long shot.
PCRM notes that “within a few years, trials had begun administering this substance to infants with lung problems” (emphasis added). What they forget to tell the reader is that a surfactant treatment wasn’t actually approved by the U.S. Food and Drug Administration until 1989(!) Finding a way to treat surfactant deficiency wasn’t quite as easy as PCRM pretends it was.
The first major treatment available was due to extensive research in sheep, not human beings. Researchers in New Zealand and the United States demonstrated that giving pregnant sheep steroids increased the rate at which fetal lungs developed, which in turn led to the development of surfactant in the lungs more quickly. Clinical trials in humans bore out the usefulness of delaying premature labor 24-48 hours and administering steroids to promote lung growth.
The introduction of ventilators in the early 1970s specifically designed to prevent lung collapse was also an important boon for the survival rates of premature infants.
Research into finding a safe, reliable surfactant replacement therapy continued through the 1970s and 1980s, much of it highly dependent on animal research. In fact when the U.S. FDA finally approved two surfactant replacement therapies, animal byproducts were the major component of one of the therapies. The natural surfactant replacement therapy is most commonly made from the extracts of calf lungs, though pig lungs and human lungs are occasionally used as a source as well. There is a synthetic surfactant available, but studies in both human beings and animals have tended to indicate that it is not as effective as that derived from bovine sources. On reason offered by the differing efficacy is the presence of proteins in the natural surfactant replacement which are absent in the synthetic replacement.
Far from animal studies being irrelevant, they played a fundamental role in developing a viable surfactant replacement therapy. So PCRM, take a deep breath and relax. Thanks to animal research, premature infants can have the same luxury.
Sources:
Why animal experiments fail in birth defects research. Physicians Committee for Responsible Medicine, undated.
Surfactant Replacement Therapy. Victor Chernick, Canadians for Health Research.
Hyaline membrane disease. Discovery.Com.
New Studies Of A Liquid Of Life — Lung Surfactant. Science Daily, August 23, 1999.
Natural surfactant extract versus synthetic surfactant for neonatal respiratory distress syndrome. Roger F. Soll, National Institutes of Health, February 1999.
Animal Rights, Research Wrongs. Steve Milloy, Fox News, June 29, 2001.