Monkeys to help answer why we get fat

By Richard Craver
MEDIA GENERAL NEWS SERVICE
Published: July 11, 2008

WINSTON-SALEM - The round tummies of vervet monkeys may play a key role in unlocking the hereditary risks of obesity in humans.
A colony of 450 members was recently moved from Los Angeles to the Wake Forest University Primate Center in Davidson County. The University of California, Los Angeles and Wake Forest collaborated on the first research paper on the colony.
The colony, which originated from vervets collected from the Caribbean island of St. Kitts, contains family trees that have been tracked for eight generations by researchers.
Because there is considerable overlap in the genotypes of the vervet species and humans, Wake Forest researchers said that the monkeys are becoming increasingly important in research on cardiovascular and metabolic disorders, aging, cancer, learning and cognition, substance abuse, vulnerability to mental disorders, reproductive medicine and infectious disease.
“They have been pedigreed for eight generations, so we know who belongs to whom genetically,” said David Friedman, an associate dean for research and a physiology professor at Wake Forest’s School of Medicine. The colony is one of only two in the country with that level of pedigree.
Where the vervets’ stomachs come into play is that researchers will soon begin feeding them the equivalent of a normal American’s diet containing more fats and sugars than their low-fat chow.
Researchers plan to give the monkeys a physical every three months, which will include measuring the width of their stomachs, their body-mass index and checking their blood for levels of cholesterol, blood glucose, lipids and insulin.
The typical male vervet weighs about 13 pounds, and the typical female weighs about 10. To be considered obese, the monkeys must have an increase of about 25 percent of their body weight.
“The colony allows us to study the development of obesity-related disorders across all life stages,” Friedman said. “All of the monkeys will be fed the same diet and be exposed to the same living conditions.”
Jan Wagner, the director of the Animal Resources Program at the university, said that the colony will enable researchers “to study whether the offspring of a skinny parent becomes obese on this diet, or their genetics allows them to maintain their inherited body type.”
Friedman said they will be able to observe the amount of time between the monkeys becoming obese and the development of diabetes and cardiovascular diseases.
“We’ll be able to measure this in terms of years for these monkeys rather than decades for humans,” he said.
The primate center is based on a 200-acre farm with an average population of about 1,500 monkeys. It also has about 100 employees, including 12 veterinarians.
Officials at the gated center provided yesterday’s open house to the media partly to show off their excitement about having the colony based here.
They also wanted to demonstrate the level of care that the monkeys get to counter the image of conditions at animal farms as portrayed by some activist groups. At the Wake Forest center, the monkeys’ outside play areas are spacious and similar to those found at zoos. Those on display appeared active and very social.
Involvement with the colony does carry some risks to the center’s employees.
A story in the Los Angeles Times in February criticized nicotine-addiction research done by UCLA on members of the colony, including the acceptance of a $6 million contribution from Philip Morris USA.
According to the newspaper, some of the UCLA researchers were victims of vandalism by activists opposed to animal testing.
“This colony has had some national attention from animal activists when it was based at UCLA,” Friedman said. “We’ve had little local attention here.
“We bend over backward to make sure the monkeys are taken care of and that protocols are followed. When a monkey gets diabetes, it is treated with insulin just like humans are.”