In:
American Journal of Physiology-Endocrinology and Metabolism, American Physiological Society, Vol. 288, No. 6 ( 2005-06), p. E1277-E1283
Abstract:
We previously reported that 2 H 2 O can be used to measure rates of protein synthesis during prolonged steady-state conditions (Previs SF, Fatica R, Chandramouli V, Alexander JC, Brunengraber H, and Landau BR. Am J Physiol Endocrinol Metab 286: E665-E672, 2004). The underlying premise of our method is that following the administration of 2 H 2 O, 2 H atoms in body water rapidly equilibrate with free alanine before it is incorporated into newly synthesized proteins. We have now directly examined whether 2 H 2 O can be used to measure the influence of a single meal on protein synthesis. In addition, we have compared the use of 2 H 2 O for measuring rates of protein synthesis in vivo vs. in cell culture. Using a rat model, we observed rapid equilibration between 2 H in body water and free alanine; therefore we were able to study the response of protein synthesis to a single meal. We observed that ∼50% of the plasma albumin that is synthesized over the course of 24 h is made within ∼5 h after eating (in rats trained to eat a complete 24-h ration of food in a single meal). Contrary to what we observed in vivo, feeding (the replenishment of cell culture medium) does influence the use of 2 H 2 O for in vitro studies. In particular, since there can be slow equilibration of 2 H between water and alanine in the cell culture medium, special consideration must be made to avoid underestimating the rate of protein synthesis in vitro.
Type of Medium:
Online Resource
ISSN:
0193-1849
,
1522-1555
DOI:
10.1152/ajpendo.00580.2004
Language:
English
Publisher:
American Physiological Society
Publication Date:
2005
detail.hit.zdb_id:
1477331-4
SSG:
12
