"As with any scientific measurement, there will be errors associated with this calculated metabolic rate," Hegg says. "Thus, having a second way to measure metabolism would be beneficial."
A potential second method could measure oxygen and perhaps hydrogen isotope ratios in a common metabolite ?a product produced by most human cells as they metabolize food and water. The ratios of the isotopes would reveal the percentage of water in body cells that was produced by metabolism, and thus the rate of metabolism.
"We could compare the ratios obtained from a 'healthy' person to the ratios obtained from an obese person," Hegg says. "One also could imagine performing similar tests on an anorexic or bulimic individual. You would be asking whether the isotope ratio of the metabolite more closely matched the food that the individual consumed or the proteins already in the individual's body. If it is the latter, then it means that the individual is basically in a starvation state, living off of their stored proteins."
Finding Hidden but Aggressive Cancers
The difference in isotope ratios in water inside and outside a cancer cell "could be useful in developing a test to assess the metabolic rate of a tumor ?how fast the tumor is growing," says Hegg. "This could be especially important in tumors in which obtaining a biopsy is difficult."
If doctors can do a biopsy to remove a sample of a tumor, the cancer cells can be cultured in a dish to determine how rapidly they grow. "But if you can't biopsy it because it's in your brain or another hard-to-reach location, then you need some other way to figure out how fast it's growing," Hegg says.
Such a test would involve t
Source:University of Utah Public Relations