Lactate transport by rainbow trout white muscle: kinetic characteristics and sensitivity to inhibitors

1997 ◽  
Vol 272 (5) ◽  
pp. R1577-R1587 ◽  
Author(s):  
Y. Wang ◽  
P. M. Wright ◽  
G. J. Heigenhauser ◽  
C. M. Wood
Keyword(s):  
Rainbow Trout ◽  
White Muscle ◽  
Fish Muscle ◽  
Retention Mechanism ◽  
Disulfonic Acid ◽  
Extracellular Concentration ◽  
Carrier Mediated Transport ◽  
Uptake Rates ◽  
Resting Muscle ◽  
And Diffusion

This study used an isolated-perfused tail-trunk preparation of rainbow trout to examine the uptake and release of lactate (Lac) and metabolic protons (delta H+M) in resting and exercised fish white muscle. In exercised muscle, L(+)-Lac efflux was inhibited (approximately 40%) by 5 mM alpha-cyano-4-hydroxycinnamate (CIN), but not by 0.5 mM 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (SITS) or 0.1 mM amiloride. These results suggest that Lac release occurs through a Lac(-)-H- symport and the free diffusion of lactic acid (HLac) or Lac-, but not via the Lac-/HCO3(-)-Cl- antiporter. Lac efflux was accompanied by delta H+m influx in all treatments, and increased delta H+m influx occurred after SITS treatment. In resting muscle, Lac uptake rates were greater than Lac efflux rates in the postexercise preparation. L-Lac influx exhibited partial saturation kinetics, whereas D(-)-Lac influx was linearly related to its extracellular concentration (0-32 mM). At 16 mM extracellular L-Lac, with a negligible transmembrane L-HLac gradient and an outwardly directed not driving force on L-Lac-, CIN, and SITS reduced net L-Lac uptake by 75 and 45%, respectively. At 16 mM extracellular concentration, D-Lac influx was 64% of the net L-Lac influx. These results suggest that in trout muscle at 16 mM extracellular L-Lac, the Lac -H+ symport accounts for 30-36%, the Lac-/HCO3(-)-Cl- antiport for 39-45%, and diffusion for 19-25% of uptake, although the latter is probably overestimated and the former underestimated for methodological reasons. Net L-Lac efflux was not affected by extracellular D-Lac concentration and/or D-Lac influx, implying the existence of a concurrent L-Lac efflux during L-Lac influx. The D-Lac influx kinetics data indicated that the Lac-/HCO3 antiport was not saturable in the extracellular D-Lac concentration range of 0-32 mM. This study clearly demonstrates the involvement of carrier-mediated transport in transmembrane Lac movement in fish muscle and supports the "active lactate retention" mechanism proposed by Turner and Wood (J. Exp. Biol. 105: 895-401, 1983).

The specificity of purine base and nucleoside uptake in promastigotes ofLeishmania braziliensis panamensis

Parasitology ◽  
1982 ◽  
Vol 85 (2) ◽  
pp. 271-282 ◽  
Author(s):  
B. D. Hansen ◽  
J. Perez-Arbelo ◽  
J. F. Walkony ◽  
L. D. Hendricks
Keyword(s):  
Competitive Interactions ◽  
Leishmania Braziliensis ◽  
Purine Base ◽  
Purine Bases ◽  
Uptake Rates ◽  
Nucleoside Uptake ◽  
And Diffusion

SUMMARYPromastigotes ofLeishmania braziliensis panamensisabsorbed the purines adenine, hypoxanthine, adenosine and inosine by a combination of diffusion and mediated components. When the uptake rates for these substrates were corrected for diffusion and compared, the purine bases adenine and hypoxanthine were transported at a significantly slower rate than the purine nucleosides adenosine and inosine. Competitive interactions among those purines tested confirmed the presence of mediated and diffusion components and suggested that three transport loci may be operating (Fig. 6). The first transport locus, designated Locus 1, transported inosine, Locus 2, the purine bases hypoxanthine and adenine and Locus 3, adenosine. In addition, adenine and hypoxanthine inhibited the uptake of one another competitively. A comparison of Kivalues derived from double reciprocal plots of labelled hypoxanthine and adenine uptake in the presence of the unlabelled substrates as inhibitors suggested that adenine has a greater affinity for the transport locus.

Palmitate movement across red and white muscle membranes of rainbow trout

2004 ◽  
Vol 286 (1) ◽  
pp. R46-R53 ◽  
Author(s):  
Jeff G. Richards ◽  
Arend Bonen ◽  
George J. F. Heigenhauser ◽  
Chris M. Wood
Keyword(s):  
Fatty Acid ◽  
Rainbow Trout ◽  
White Muscle ◽  
Specific Inhibitor ◽  
Fatty Acid Binding ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Fatty Acid Transporter ◽  
Palmitate Uptake ◽  
High Concentrations

We examined the movement of [3H]palmitate across giant sarcolemmal vesicles prepared from red and white muscle of rainbow trout ( Oncorhynchus mykiss). Red and white muscle fatty acid carriers have similar affinities for palmitate (apparent Km = 26 ± 6 and 33 ± 8 nM, respectively); however, red muscle has a higher maximal uptake compared with white muscle ( Vmax = 476 ± 41 vs. 229 ± 23 pmol·mg protein-1·s-1, respectively). Phloretin (250 μM) inhibited palmitate influx in red and white muscle vesicles by ∼40%, HgCl2 (2.5 mM) inhibited palmitate uptake by 20-30%, and the anion-exchange inhibitor DIDS (250 μM) inhibited palmitate influx in red and white muscle vesicles by ∼15 and 30%, respectively. Western blot analysis of red and white muscle vesicles did not detect a mammalian-type fatty acid transporter (FAT); however, preincubation of vesicles with sulfo- N-succinimidyloleate, a specific inhibitor of FAT in rats, reduced palmitate uptake in red and white muscle vesicles by ∼15 and 25%, respectively. A mammalian-type plasma membrane fatty acid-binding protein was identified in trout muscle using Western blotting, but the protein differed in size between red and white muscle. At low concentrations of free palmitate (2.5 nM), addition of high concentrations (111 μM total) of oleate (18:0) caused ∼50% reduction in palmitate uptake by red and white muscle vesicles, but high concentrations (100 μM) of octanoate (8:0) caused no inhibition of uptake. Five days of aerobic swimming at ∼2 body lengths/s and 9 days of chronic cortisol elevation in vivo, both of which stimulate lipid metabolism, had no effect on the rate of palmitate movement in red or white muscle vesicles.

scholarly journals Changes in white muscle transcriptome induced by dietary energy levels in two lines of rainbow trout (Oncorhynchus mykiss) selected for muscle fat content

2009 ◽  
Vol 103 (5) ◽  
pp. 629-642 ◽  
Author(s):  
Catherine-Ines Kolditz ◽  
Elisabeth Plagnes-Juan ◽  
Edwige Quillet ◽  
Florence Lefèvre ◽  
Françoise Médale
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
White Muscle ◽  
Energy Levels ◽  
High Energy ◽  
Fat Content ◽  
Fat Deposition ◽  
Dietary Energy ◽  
Expression Change ◽  
Vldl Receptor

Energy intake and genetic background are major determinants of muscle fat content in most animals, including man. We combined genetic selection and dietary energy supply to study the metabolic pathways involved in genetic and nutritional control of fat deposition in the muscle of rainbow trout (Oncorhynchus mykiss). Two experimental lines of rainbow trout, selected for lean (L) or fat (F) muscle, were fed with diets containing either 10 or 23 % lipids from the first feeding, up to 6 months. At the end of the trial, trout exhibited very different values of muscle fat content (from 4·2 to 10·1 % wet weight). Using microarrays made from a rainbow trout multi-tissue cDNA library, we analysed the molecular changes occurring in the muscle of the two lines when fed the low-energy or high-energy diet. The results from microarray analysis revealed that eleven metabolism-related genes were differentially expressed according to the diet while selection resulted in expression change for twenty-six genes. The most striking observation was the increased level of transcripts encoding the VLDL receptor and fatty acid translocase/CD36 following both the high-fat diet and upward selection for muscle fat content, suggesting that these two genes are relevant molecular markers of fat deposition in the white muscle of rainbow trout.

Dissolution of Fish Muscle Homogenates by Lysolecithin

1968 ◽  
Vol 25 (10) ◽  
pp. 2157-2164
Author(s):  
R. E. E. Jonas
Keyword(s):  
Skeletal Muscle ◽  
Rainbow Trout ◽  
Snake Venom ◽  
Incubation Medium ◽  
Fish Muscle ◽  
N Content ◽  
Snake Venom Phospholipase ◽  
Solubilizing Activity ◽  
Supernatant Solution ◽  
Muscle Homogenate

On incubating skeletal muscle homogenates from rainbow trout with lysolecithin (LL) and comparing them with homogenates of the same muscle without added LL, and after centrifuging the mixtures, it was found that the N content of the supernatant solution of the homogenate containing LL was about 20% higher than that of the homogenate without LL. Increases close to maximum in N content of the supernatant solution were found to occur at a concentration of about 4 mg LL per ml of incubation medium containing 100 mg muscle in 3.0 ml of 0.9% NaCl at a pH of 6.0–8.0 and at about 35 C for a period of 1 hr. Snake venom phospholipase A added to muscle homogenate showed no solubilizing activity and α-tocopherol acetate and cortisol showed irregular stimulation. It was concluded that LL exerts a solubilizing action on fish muscle homogenates.

White Muscle Intracellular Acid-Base and Lactate Status Following Exhaustive Exercise: A Comparison between Freshwater- and Sea Water- Adapted Rainbow Trout

1991 ◽  
Vol 156 (1) ◽  
pp. 153-171 ◽  
Author(s):  
YONG TANG ◽  
ROBERT G. BOUTILIER
Keyword(s):  
Rainbow Trout ◽  
White Muscle ◽  
Sea Water ◽  
Ph Regulation ◽  
Recovery Period ◽  
Exhaustive Exercise ◽  
Acid Base ◽  
Post Exercise ◽  
Acid Base Status ◽  
Intracellular Acid

The intracellular acid-base status of white muscle of freshwater (FW) and seawater (SW) -adapted rainbow trout was examined before and after exhaustive exercise. Exhaustive exercise resulted in a pronounced intracellular acidosis with a greater pH drop in SW (0.82 pH units) than in FW (0.66 pH units) trout; this was accompanied by a marked rise in intracellular lactate levels, with more pronounced increases occurring in SW (54.4 mmoll−1) than in FW (45.7 mmoll−1) trout. Despite the more severe acidosis, recovery was faster in the SW animals, as indicated by a more rapid clearance of metabolic H+ and lactate loads. Compartmental analysis of the distribution of metabolic H+ and lactate loads showed that the more rapid recovery of pH in SW trout could be due to (1) their greater facility for excreting H+ equivalents to the environmental water [e.g. 15.5 % (SW) vs 5.0 % (FW) of the initial H+ load was stored in external water at 250 min post-exercise] and, to a greater extent, (2) the more rapid removal of H+, facilitated via lactate metabolism in situ (white muscle) and/or the Cori cycle (e.g. heart, liver). The slower pH recovery in FW trout may also be due in part to greater production of an ‘unmeasured acid’ [maximum approx. 8.5 mmol kg−1 fish (FW) vs approx. 6 mmol kg−1 fish (SW) at 70–130 min post-exercise] during the recovery period. Furthermore, the analysis revealed that H+-consuming metabolism is quantitatively the most important mechanism for the correction of an endogenously originating acidosis, and that extracellular pH normalization gains priority over intracellular pH regulation during recovery of acid-base status following exhaustive exercise.

scholarly journals The Effect of Slaughtering Procedures on Blood Spotting in Rainbow Trout (Oncorhynchus Mykiss)

2011 ◽  
Vol 68 (2) ◽  
Author(s):  
George Liviu MIHALCA ◽  
Mihaela TIŢA ◽  
Ana MIHALCA ◽  
Ovidiu TIŢA
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Fish Muscle ◽  
Rigor Mortis ◽  
Visual Appearance ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Colour Measurements ◽  
Significant Difference

Rainbow trout (Oncorhynchus mykiss) was submitted for various slaughter and bleeding procedures to see what effect this would have on blood drainage of the muscles. Results show that the bleeding method is of less importance, while it is the timing that is important. No significant difference in bloodspotting was observed between fish that were bled live by a gill cut or percussive killed and bled by gutting. Most of the drainage of blood in the fish muscle seems to occur within the first hours postmortem, so rigor mortis is of little importance. The visual appearance of the fillet was influenced by number and size of the bloodstains. Colour measurements with Hunter L*, a*, b* did not reveal this. We conclude that a gill cut is not necessarily to obtain bleeding, so the industry can omit this phase and go directly to gutting.

Oxidation of Lactate to Carbon Dioxide by Rainbow Trout (Salmo gairdneri) Tissues

1972 ◽  
Vol 29 (10) ◽  
pp. 1467-1471 ◽  
Author(s):  
E. Bilinski ◽  
R. E. E. Jonas
Keyword(s):  
Rainbow Trout ◽  
White Muscle ◽  
Salmo Gairdneri ◽  
Oxidative Decarboxylation ◽  
Complete Oxidation ◽  
Exchange Reactions ◽  
Fish Tissues ◽  
Tissue Slices ◽  
Lactate Oxidation ◽  
Level Of Activity

A comparative study on the ability of various fish tissues to carry out different stages of lactate oxidation was conducted with rainbow trout (Salmo gairdneri). Rate of oxidation of Na-L-lactate-1-14C (5 mM) and Na-L-lactate-3-14C (5 mM) by tissue slices from white muscle, red lateral line muscle, heart, liver, kidney, and gills was determined at 15 C by measuring the formation of 14CO2. In all tissues the liberation of 14CO2 was considerably higher with lactate-1-14C than with lactate-3-14C. Liver was the most active tissue for oxidation of lactate-1-14C (2805 mμmoles/g wet tissue/hr at 15 C) and gills for oxidation of lactate-3-14C (556 mμmoles/g wet tissue/hr at 15 C). With both substrates activity in the white muscle was very limited, whereas other tissues had an intermediate level of activity. The results suggest that, in trout, the catabolism of lactate may take place through oxidative decarboxylation of pyruvate and that liver plays an important role in such a process. It appears also that complete oxidation of lactate may be of significance in supplying energy for the exchange reactions in gills.

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