|
| |
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
Journal of Experimental Biology, Vol 177, Issue 1 63-79, Copyright © 1993 by Company of Biologists
JOURNAL ARTICLES |
T. G. West, P. G. Arthur, R. K. Suarez, C. J. Doll and P. W. Hochachka
In vivo rates of glucose utilization were estimated in red muscle and heart of rainbow trout using the radiolabeled glucose analogue, [14C]-2-deoxyglucose ([14C]-2-DG). The 2-DG 'lumped constant' (LC), representing the uptake ratio between 2-DG and glucose for each tissue, was determined in vitro using tissue slices. For both red muscle and heart, the LC was approximately 0.40. In addition, changes in circulatory glucose utilization induced in an isolated trout heart preparation had no effect on the LC. The LC was applied to calculations of in vivo rates of circulatory glucose disposal in muscle tissue of resting and swimming trout. Utilization was estimated at 0.87+/-0.15 and 5.31+/-1.04 nmol g-1 min-1 in red muscle and heart of resting fish, respectively. In trout swimming at 80 % Ucrit, glucose utilization in heart was unchanged compared to resting controls, while red muscle utilization increased by 28-fold. Estimates of the oxidative demand of heart and locomotory muscle of swimming trout indicate that glucose utilization accounted for less than 10 % of the energy production in both tissues. In trout heart, in vitro measures of glucose flux suggest an apparent excess capacity to use circulatory glucose. Preference for other intra- and extramuscular fuels may partially explain limited glucose utilization, but it remains unclear to what degree, and under what conditions, glucose utilization may be increased in vivo.
This article has been cited by other articles:
|
|
 |
|
  C. Kolditz, M. Borthaire, N. Richard, G. Corraze, S. Panserat, C. Vachot, F. Lefevre, and F. Medale Liver and muscle metabolic changes induced by dietary energy content and genetic selection in rainbow trout (Oncorhynchus mykiss) Am J Physiol Regulatory Integrative Comp Physiol, April 1, 2008; 294(4): R1154 - R1164. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. J. MacCormack and W. R. Driedzic The impact of hypoxia on in vivo glucose uptake in a hypoglycemic fish, Myoxocephalus scorpius Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2007; 292(2): R1033 - R1042. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Frolow and C. L. Milligan Hormonal regulation of glycogen metabolism in white muscle slices from rainbow trout (Oncorhynchus mykiss Walbaum) Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2004; 287(6): R1344 - R1353. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. A. Clow, K. J. Rodnick, T. J. MacCormack, and W. R. Driedzic The regulation and importance of glucose uptake in the isolated Atlantic cod heart: rate-limiting steps and effects of hypoxia J. Exp. Biol., May 1, 2004; 207(11): 1865 - 1874. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. L. Milligan A regulatory role for cortisol in muscle glycogen metabolism in rainbow trout Oncorhynchus mykiss Walbaum J. Exp. Biol., September 15, 2003; 206(18): 3167 - 3173. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. R. Wright Jr., A. Bonen, J. Michael Conlon, and B. Pohajdak Glucose Homeostasis in the Teleost Fish Tilapia: Insights from Brockmann Body Xenotransplantation Studies Integr. Comp. Biol., April 1, 2000; 40(2): 234 - 245. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. K. Suarez, J. F. Staples, J. R. B. Lighton, and T. G. West Relationships between enzymatic flux capacities and metabolic flux rates: Nonequilibrium reactions in muscle glycolysis PNAS, June 24, 1997; 94(13): 7065 - 7069. [Abstract] [Full Text] [PDF]
|
|
