Molybdenum metabolism in young men fed a range of dietary
molybdenum intakes: changes in kinetic parameters.
Thompson, Katherine H., Karen C. Scott, and Judith R. Turnlund.
USDA/ARS Western Human Nutrition Research Center, P.O. Box 29997,
Presidio of San Francisco, CA 94129-0997
APStracts 3:0202A, 1996.
Molybdenum metabolism was studied in four young men to determine the
effect of the amount of dietary molybdenum on molybdenum kinetics. A
compartmental model, developed using data from a study with low
dietary molybdenum, was adapted to accommodate 5 levels of
molybdenum. Each level, ranging from 22 - 1470 [mu]g Mo/day, was fed
for 24 days. Kinetics of absorption and excretion were traced using
97Mo (intravenous) and 100Mo (oral) stable isotope tracers at
selected intervals. Urinary and fecal isotope excretion data for 6
-day pooled collections were fit to a kinetic model using SAAM/CONSAM
software. Residence times for molybdenum were estimated at 2.4 days
in the GI tract, 40 min in plasma, from 3.3 to 0.3 days in fast
-turnover tissue, and from 63 to 237 days in slow-turnover tissue. As
dietary molybdenum increased, residence time decreased in fast
-turnover tissue and increased in slow-turnover tissue. The model
closely approximated the highly efficient homeostatic mechanisms of
molybdenum metabolism over a wide range of intakes.
Received 8 December 1995; accepted in final form 29 March 1996.
APS Manuscript Number A1282-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 23 April 96