scholarly journals Oxygen Consumption and Hypoxic Tolerance of Triploid Rainbow Trout.

1994 ◽  
Vol 29 (4) ◽  
pp. 245-251 ◽  
Author(s):  
Atsushi Yamamoto ◽  
Takaji Iida
Keyword(s):  
Oxygen Consumption ◽  
Rainbow Trout ◽  
Hypoxic Tolerance

Influence of low temperature acclimation on fate of metabolic fuels in rainbow trout (Oncorhynchus mykiss) hearts

1993 ◽  
Vol 71 (11) ◽  
pp. 2167-2173 ◽  
Author(s):  
John R. Bailey ◽  
William R. Driedzic
Keyword(s):  
Oxygen Consumption ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Temperature Acclimation ◽  
Experimental Conditions ◽  
Intracellular Lipids ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Significant Difference ◽  
Precipitate Protein ◽  
Fuel Source

Rainbow trout (Oncorhynchus mykiss) were acclimated to 5 and 20 °C. Oxygen consumption of isolated perfused hearts was measured at 5 or 15 °C with either glucose or palmitate as the exogenous fuel source. With glucose as the fuel there was no significant difference in oxygen consumption of hearts from either acclimation group at either temperature. With palmitate as the fuel source, hearts from fish acclimated to and tested at 5 °C had significantly higher oxygen consumption than hearts from fish acclimated to 20 °C and tested at either 5 or 15 °C. Hearts from fish both acclimated to and tested at 5 °C had a higher oxygen consumption with palmitate than when glucose was supplied. This reflects the preference for fatty acid fuels found in cold acclimated muscle tissue, and consequently the amount of oxygen required to utilize fats. Under all experimental conditions, 14CO2 production from either (6-14C)glucose or (1-14C)palmitate could account for less than 0.5% of oxygen consumption. Tissue chemical analysis showed that most of the label from (6-14C)glucose appeared in acid-soluble (glycolytic intermediates, citric acid cycle intermediates, amino acids, etc.) and lipid fractions while most of the label from (1-14C)palmitate appeared in lipid- or acid-soluble or acid precipitate (protein material) fractions. This indicates considerable dilution of exogenous fuels in endogenous pools, which could account for the discrepancy in measured O2 consumption and 14CO2 production. Glucose catabolism was little affected by either acute or chronic changes in temperature other than an increase in glucose incorporation into the glycogen pool. Hearts from fish both acclimated to and tested at 5 °C showed an increased handling of exogenous fatty acids as reflected by elevated rates of catabolism and incorporation into intracellular lipids.

scholarly journals Gas exchange, metabolite status and excess post-exercise oxygen consumption after repetitive bouts of exhaustive exercise in juvenile rainbow trout

1992 ◽  
Vol 167 (1) ◽  
pp. 155-169 ◽  
Author(s):  
M. Scarabello ◽  
G. J. Heigenhauser ◽  
C. M. Wood
Keyword(s):  
Oxygen Consumption ◽  
Rainbow Trout ◽  
Exercise Bout ◽  
Creatine Phosphate ◽  
Lactate Clearance ◽  
Exhaustive Exercise ◽  
Oxygen Debt ◽  
Whole Body ◽  
Post Exercise ◽  
Lactate Levels

Juvenile rainbow trout (approximately 6 g) were exercised to exhaustion in two 5 min bouts given 6 h apart. Resting levels of whole-body lactate and glycogen were restored prior to the second bout. The rate of O2 consumption increased about threefold 5 min after each bout of exercise, while recovery time decreased from 4 h after the first bout to 2–3 h after the second. The excess post-exercise oxygen consumption, i.e. ‘oxygen debt’, was significantly reduced by 40% after the second exercise bout, despite almost identical rates of lactate clearance and glycogen resynthesis. The rates of CO2 and ammonia excretion increased sixfold and threefold, and recovery times decreased from 4–6 h to 3 h and from 3 h to 1.5 h, respectively. After the first bout, whole-body lactate levels peaked at 5 min post-exercise at about 8.5 times pre-exercise levels. After the second bout, lactate levels peaked at 0 min post-exercise and fell more rapidly during recovery. Whole-body glycogen levels decreased by 70% and 80% and ATP levels decreased by 75% and 65% after the first and second bouts, respectively, while glucose levels increased about 1.5-fold immediately after both bouts. Creatine phosphate levels decreased by 70% and 80% after the first and second bouts, respectively. After 6 h of recovery, creatine phosphate levels were higher after the second bout than after the first. These findings suggest that exhaustive exercise may cause a ‘non-specific’ increase in metabolic rate not directly related to the processing of metabolites, which is reduced upon a subsequent exercise bout. This is in contrast with the classical ‘oxygen debt hypothesis’, which states that the oxygen debt and lactate clearance are linked. Furthermore, it appears that two sequential exercise bouts are sufficient to induce a ‘training effect’, i.e. improved rates of metabolic recovery.

scholarly journals GLUCOSE METABOLISM BY SEA RAVEN (HEMITRIPTERUS AMERICANUS) AND RAINBOW TROUT (ONCORHYNCHUS MYKISS) ERYTHROCYTES

1994 ◽  
Vol 194 (1) ◽  
pp. 167-180 ◽  
Author(s):  
D Sephton ◽  
W Driedzic
Keyword(s):  
Oxygen Consumption ◽  
Rainbow Trout ◽  
Metabolic Rate ◽  
Glucose Disappearance ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Sea Raven ◽  
Extracellular Glucose ◽  
14Co2 Production ◽  
Hemitripterus Americanus

The fate of extracellular glucose in blood isolated from sea raven (Hemitripterus americanus) and rainbow trout (Onchorhynchus mykiss) was determined. In blood from both species incubated in vitro at low physiological pH, the decrease in plasma glucose concentration was more than adequate to support oxygen consumption. Glucose disappearance could not be accounted for by increases in lactate, red blood cell (RBC) glucose or RBC glycogen concentrations. Rates of 14CO2 production from [6-14C]glucose over a 2 h incubation period were less than 1 % of metabolic rate. Only small amounts of label appeared in RBC protein, lipid or glycogen fractions relative to metabolic rates, but label accumulated in the intracellular acid-soluble fraction (presumably free glucose, glycolytic intermediates, amino acids, citric acid cycle intermediates, etc.) at rates consistent with oxygen consumption and glucose disappearance. The simplest explanation for the mismatch between 14CO2 production and the other estimates of metabolic rate is that incubation times were too short for equilibration to occur. A consequence is that studies of this nature cannot use 14CO2 production to elucidate rates of aerobic fuel utilization. By default, the data imply that glucose serves as a primary aerobic metabolic fuel for the RBCs, at least under some conditions.

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