MADISON, WI June 22, 2012 Buttery shrimp. Fried eggs. Burgers and fries. New research suggests there may be a biological reason why fatty and cholesterol-rich foods are so appealing together.
It has been known for more than 40 years that dietary fat promotes cholesterol uptake, but fundamental aspects of that process remain poorly understood. James Walters, Ph.D., and his colleagues at the Carnegie Institution for Science are using zebrafish to better understand the cellular mechanisms of cholesterol processing and have discovered a surprising link between dietary fat and cholesterol absorption.
"One reason these questions remain unknown is because of the difficulty of studying such a complex biological system as the intestine," which in addition to multiple cell types also includes a diverse array of enzymes, mucus, and symbiotic bacteria, he said in a June 20 presentation at the ongoing 2012 International Zebrafish Development and Genetics Conference in Madison, Wisconsin.
As a postdoctoral fellow in Dr. Steven Farber's lab at the Carnegie Institution for Science, in Baltimore, Maryland, Dr. Walters turned to young zebrafish, which provide a biologically complete and scientifically accessible system for studying the workings of the gut.
"Because the larval zebrafish are optically clear, we can visualize fat transport and processing by looking right through their body wall into the intestine where the action is," Dr. Walters said.
He developed a way to feed zebrafish a diet high in lipids (e.g., fat and cholesterol) or high in protein and low in lipids. He accomplished this by turning to the chicken egg, whipping fish water with the yolk for a high-lipid diet and the egg white as a high-protein diet. Before feeding these diets, fluorescently tagged cholesterol or fatty acid was added, enabling the microscopic viewing of how lipids are absorbed and processed by the intestinal cells.
Dr. Walters found th
|Contact: Phyllis Edelman|
Genetics Society of America