New Techniques in Nutritional Research

• Main Author: Whitehead, Roger (Author)
• Corporate Author: Bristol-Myers Squibb/Mead Johnson Symposium on Nutrition Research
• Other Authors: Prentice, Ann
• Format: Book
• Language: English
• Published: San Diego Academic Press 1991; ©1991
• Series: Bristol-Myers Squibb/Mead Johnson nutrition symposia 9
• Subjects: Stable isotope tracers > Congresses; Nutrition > Research > Methodology > Congresses
• Online Access: Click Here to View Status and Holdings.

 One possible salvation lies in an increase in the accuracy, precision, and ensitivity of instrumentation to enable isotopic enrichments to be m wured at values much nearer the background. The development of t gas-chromatograph isotope-ratio mass spectrometer (Matthews and Hayes, 1978) is a step in this direction, although a commercially availabl instrument has been some time coming. Present conformations of avail able instruments have some inherent disadvantages such as the need to rely on absolutely reproducible elutiontimes during chromatography order to measure the isotope ratio of particular labeled moieties. This means a substantial lessening of analysis throughout since pure samples have to be run frequently as standards. Theoretically, given sufficient sensitivity, those tracers that are present at the lowest natural abundance in the environment will have the greatest utility as tracers, and vice versa. Thus a major disadvantage to the use of stable isotope-labeled compounds in comparison with radioactive-labeled compounds is the small dynamic range available for measurement; for example, "C is present at a background abundance of about 1%, which is much greater than the natural abundance of 14C. This limits the extent to which metabolites can be labeled within biological systems, thus throwing the emphasis onto instrument sensitivity for advances. Similar problems exist for other tracers. Perhaps the use of extremely sensitive mass spectrometers such as those used for carbon dating will offer the possibility of using vanishingly small amounts of "C as biological tracers at concentrations likely to pose conceivable health risk. no The development of instruments with increased sensitivity, accuracy, and precision will continue, and one technique that is likely to make an increasingly substantial impact is magnetic resonance (Alger et al, 1981) especially if spectroscopy can be carried out on visually defined elements perhaps using proton nuclear magnetic resonance. Carbohydrate metabo lism appears to be the area in which advances are most likely to occur. The potential for application in studies of normal and disease processes i substantial.