Metabolic organization of liver and somatic muscle of landlocked sea lamprey,Petromyzon marinus, during the spawning migration

1995 ◽  
Vol 73 (5) ◽  
pp. 916-923 ◽  
Author(s):  
P. J. LeBlanc ◽  
T. E. Gillis ◽  
M. F. Gerrits ◽  
J. S. Ballantyne

The metabolic organization of liver and muscle of the landlocked sea lamprey, Petromyzon marinus, during the spring spawning migration was assessed by measuring activities of key enzymes for several metabolic pathways, the oxidative properties of mitochondria, and plasma concentrations of nonesterified fatty acids (NEFAs) and free amino acids. These determinations indicate that several metabolic sources are used to fuel the energy requirements of muscle. Lamprey muscle has a high capacity to oxidize lipids but the plasma NEFAs are lower than those reported for other species. Of the NEFAs measured in plasma, 18:0 was prominent, accounting for 23% of the total NEFA content of the plasma. High plasma concentrations of ketogenic amino acids and high levels of tissue ketogenic/ketolytic enzyme activities indicate that ketone bodies may also be a major fuel source for migrating sea lampreys. Based on mitochondrial oxidation and enzyme measurements, glutamine catabolism in somatic muscle of lampreys is less important than in other fish red muscle.

1991 ◽  
Vol 274 (2) ◽  
pp. 395-400 ◽  
Author(s):  
K Melde ◽  
S Jackson ◽  
K Bartlett ◽  
H S A Sherratt ◽  
S Ghisla

We describe the effects of methylenecyclopropylglycine in fasted rats. A 75% decrease in the blood glucose concentration and an increase of lactate and pyruvate were observed 6 h after administration of 100 mg of this amino acid/kg. By contrast with the effects reported for hypoglycin [Williamson & Wilson (1965) Biochem. J. 94, 19c-21c], the plasma concentrations of ketone bodies decreased after administration of methylenecyclopropylglycine and the concentrations of branched-chain amino acids in the plasma were increased 6-fold. The oxidation of decanoylcarnitine or of palmitate was nearly completely inhibited in rat liver mitochondria from methylenecyclopropylglycine-poisoned rats. The activities of acetoacetyl-CoA and of 3-oxoacyl-CoA thiolase were decreased to 25% and less than 10% of the controls. There was a pronounced aciduria, due to the excretion of dicarboxylic acids and of oxidation products of branched-chain amino acids. The accumulation of the toxic metabolite methylenecyclopropylformyl-CoA in the mitochondrial matrix was detected after administration of methylenecyclopropylglycine. Similarly we confirmed experimentally that methylenecyclopropylacetyl-CoA accumulates in mitochondria incubated with methylenecyclopropylpyruvate.


1973 ◽  
Vol 51 (1) ◽  
pp. 101-104 ◽  
Author(s):  
Edward Kott

During the spawning migration, the overall color of the sea lamprey (Petromyzon marinus L.) becomes progressively more orange. This color development is not due to the chromatophores of the dermis, since the pigment involved is present in either the epidermis and (or) the outer mucus layer. The color, instead, is resultant upon an increase in the concentration of bilirubin, a bile pigment produced as a breakdown product of hemoglobin.


Hydrobiologia ◽  
2007 ◽  
Vol 582 (1) ◽  
pp. 121-132 ◽  
Author(s):  
N. O. Andrade ◽  
B. R. Quintella ◽  
J. Ferreira ◽  
S. Pinela ◽  
I. Póvoa ◽  
...  

1979 ◽  
Vol 56 (6) ◽  
pp. 563-573 ◽  
Author(s):  
H. B. Stoner ◽  
K. N. Frayn ◽  
R. N. Barton ◽  
C. J. Threlfall ◽  
R. A. Little

1. The plasma concentrations of glucose, lactate, amino acids, non-esterified fatty acids, glycerol, ketone bodies, ethanol, cortisol and insulin were measured in patients within a few hours of injury and before treatment. The severity of the injuries was assessed by the Injury Severity Score (ISS) method. 2. Plasma lactate and glucose concentrations both rose significantly with increasing ISS. 3. The concentrations of non-esterified fatty acids and glycerol were greater after moderate (ISS 7–12) than after minor (ISS 1–6) injuries. The glycerol concentrations were no higher and the non-esterified fatty acid concentrations were lower after severe (ISS > 12) than after moderate injuries. The concentrations of total ketone bodies tended to follow those of non-esterified fatty acids and there was a highly significant correlation between them. 4. The total concentration of amino acids was not affected by the severity of injury and there were no systematic changes in the concentrations of individual ones. 5. Plasma insulin concentrations were very variable and not related to severity. A weak correlation with the plasma glucose concentration seen after minor and moderate injuries was lost in the severely injured. 6. The plasma cortisol concentration was positively related to ISS up to ISS 12 but negatively so in the severely injured. 7. Factors such as age, sex and time after last meal were investigated. The most important factor modifying the response was intake of ethanol, which reduced the plasma concentrations of glucose, non-esterified fatty acids and alanine and raised that of lactate as well as the [β-hydroxybutyrate]/[acetoacetate] ratio.


2017 ◽  
Vol 27 (4) ◽  
pp. 764-772 ◽  
Author(s):  
A. D. Nunn ◽  
R. J. Taylor ◽  
I. G. Cowx ◽  
R. A. A. Noble ◽  
J. D. Bolland ◽  
...  

1983 ◽  
Vol 245 (6) ◽  
pp. R827-R830 ◽  
Author(s):  
C. J. French ◽  
P. W. Hochachka ◽  
T. P. Mommsen

Although earlier studies have established broad outlines of biochemical changes during salmon spawning migration, the metabolic organization of specific organs has hitherto remained unknown. In this study, we assessed the performance of isolated liver cells from anorexic female sockeye salmon (Oncorhynchus nerka) at four sampling sites along their 1,150-km spawning migration. Isolated hepatocytes maintain high rates of gluconeogenesis and CO2 release from amino acids and lactate throughout the migration. Alanine, derived from proteolysis of white muscle, constitutes the single most important source for de novo synthesis of glucose. Just before spawning, when glycogen reserves reach a maximum, gluconeogenesis from alanine is specifically inhibited, whereas its conversion to CO2 and the utilization of other substrates are relatively unchanged. Spawning, apparently supported by carbohydrate catabolism, is accompanied by depletion of glycogen reserves from muscle as well as liver and a stimulation of gluconeogenesis from amino acids. At the onset of migration, palmitate oxidation accounts for about half the CO2 released by liver cells; its contribution decreases during the migration and is negligible after spawning.


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