Red muscle function and thermal acclimation to cold in rainbow smelt, Osmerus mordax , and rainbow trout, Oncorhynchus mykiss

Author(s):  
Jacie L. Shuman ◽  
David J. Coughlin
1993 ◽  
Vol 71 (2) ◽  
pp. 248-251 ◽  
Author(s):  
K.-H. Kiessling ◽  
A. Kiessling

This study was undertaken to establish whether fatty acids are generally oxidized at the same rate or if a pattern of oxidation rates exists to protect certain fatty acids from degradation for ATP formation. Beta-oxidation was studied in red muscle mitochondria of 10 major fatty acids that are acquired in the diet and occur in the fat depots of rainbow trout (Oncorhynchus mykiss Walbaum). The mitochondria were isolated by fractional centrifugation and the fatty acids were added as coenzyme A esters in the presence of carnitine. The fatty acids could be separated into roughly three groups in relation to their oxidation rates. Two fatty acids (14:0 and 16:0) were oxidized as rapidly as pyruvate. Another six acids (16:1 n − 7, 18:0, 18:1 n − 9, 20:1 n − 9, 22:1 n − 9 and 22:6 n − 3) were oxidized at about three-quarters to one-half the rate of pyruvate. The two essential fatty acids (18:2 n − 6 and 18:3 n − 3) had a slow oxidation rate, about one-fifth of that of pyruvate. The liver mitochondria from rainbow trout oxidized 18:0, 18:1, 18:2, and 18:3 at the same rate, 70–80% of that of pyruvate. These results show that rainbow trout red muscle discriminates between fatty acids used in energy production and essential fatty acid precursors, as indicated by the low β-oxidation rate of the latter acids.


Author(s):  
Hillary M. Carpenter ◽  
Lisbeth S. Fredrickson ◽  
David E. Wllliams ◽  
Donald R. Buhler ◽  
Lawrence R. Curtis

1998 ◽  
Vol 201 (21) ◽  
pp. 2961-2970 ◽  
Author(s):  
J. St-Pierre ◽  
P. M. Charest ◽  
H. Guderley

This study examined whether changes in the properties of mitochondria from red muscle of rainbow trout Oncorhynchus mykiss are accompanied by ultrastructural changes during cold acclimatisation. We compared measurements at five levels of organisation in red muscle of winter- (1 °C) and summer- (16 °C) acclimatised trout. We examined (1) maximal rates of pyruvate and palmitoyl carnitine oxidation by isolated mitochondria, (2) enzymatic activities [cytochrome c oxidase (CCO), citrate synthase (CS), carnitine palmitoyl transferase (CPT) and phosphofructokinase (PFK)] of the muscle and isolated mitochondria, (3) mitochondrial protein content in the muscle, (4) the ultrastructure of muscle fibres, and (5) the cristae surface density of the mitochondria. All variables were measured on each trout sampled. The mitochondria from winter-acclimatised trout possessed higher maximal capacities for the oxidation of pyruvate and palmitoyl carnitine than those from summer-acclimatised trout. Muscle activities of CCO, CS and CPT were greater in winter than in summer trout, whereas the levels of PFK did not differ seasonally. Similarly, the mitochondria from winter trout had elevated levels of CCO, CS and CPT compared with those isolated from summer trout. The cristae surface density of the mitochondria from winter trout (40.2+/-0.6 micrometre2 micrometre-3; mean +/- s.e.m.) was significantly higher than that from summer trout (36.4+/-1.2 micrometre2 micrometre-3), whereas there was no difference in the mitochondrial volume densities of muscle fibres from winter and summer trout. Thus, the considerable compensation of muscle aerobic capacity at low temperatures in trout is not accompanied by changes in mitochondrial volume density, but rather by shifts in enzyme levels and cristae surface density.


2020 ◽  
Vol 223 (12) ◽  
pp. jeb215210 ◽  
Author(s):  
Rachel L. Sutcliffe ◽  
Shaorong Li ◽  
Matthew J. H. Gilbert ◽  
Patricia M. Schulte ◽  
Kristi M. Miller ◽  
...  

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