Kinetics of lactate transport in sarcolemmal giant vesicles obtained from human skeletal muscle

1994 ◽  
Vol 76 (3) ◽  
pp. 1031-1036 ◽  
Author(s):  
C. Juel ◽  
S. Kristiansen ◽  
H. Pilegaard ◽  
J. Wojtaszewski ◽  
E. A. Richter
Keyword(s):  
Lactate Concentration ◽  
Low Ph ◽  
Marker Enzyme ◽  
Lactate Transport ◽  
Giant Vesicles ◽  
Biopsy Material ◽  
Muscle Lactate ◽  
Transport Studies ◽  
Equilibrium Exchange ◽  
Vesicular Membrane

We developed a method that allows the measurement of muscle lactate transport in humans. The transport studies were carried out with giant (1.8- to 36-microns-diam) sarcolemmal vesicles obtained by collagenase treatment of needle biopsy material. Marker enzyme analyses demonstrated that the vesicular membrane is predominantly of sarcolemmal origin, contamination with sarcoplasmic reticulum membranes is very low, and mitochondrial membranes are not a major contaminant. The vesicles were loaded with labeled lactate, and the efflux was measured. The system displayed saturation kinetics and inhibitor sensitivity. In equilibrium exchange experiments (pH 7.4, 21 degrees C), the Michaelis-Menten constant (Km) for the carrier-mediated flux was 30 +/- 8 (SD) mM and maximal transport rate (Vmax) was 184 +/- 24 pmol.cm-2.s-1 (142 nmol.mg protein-1.min-1). In zero-trans efflux experiments, Km was 24 +/- 8 mM and Vmax was 81 +/- 11 pmol.cm-2.s-1 (63 nmol.mg protein-1.min-1). In infinite-cis experiments with a variable lactate concentration on the outside of the vesicles, Km was 8 +/- 4 mM and Vmax was 136 +/- 9 pmol.cm-2.s-1 (105 nmol.mg protein-1.min-1). Thus, the system displayed transacceleration. Low pH (6.4) had no significant effect on equilibrium exchange experiments, whereas in zero-trans experiments low pH at the trans side inhibited the flux by 50%. We concluded that lactate transport can be studied in giant vesicles obtained from a single human muscle biopsy. Our data provide evidence for the existence of a lactate carrier in human sarcolemma. This transport system must be taken into account in models of human lactate kinetics.

Lactate transport studied in sarcolemmal giant vesicles from rats: effect of training

1993 ◽  
Vol 264 (2) ◽  
pp. E156-E160 ◽  
Author(s):  
H. Pilegaard ◽  
C. Juel ◽  
F. Wibrand
Keyword(s):  
Skeletal Muscles ◽  
Maximal Oxygen Consumption ◽  
Control Level ◽  
Treadmill Training ◽  
Marker Enzyme ◽  
Lactate Transport ◽  
Giant Vesicles ◽  
Equilibrium Exchange ◽  
The Individual ◽  
Intensity Training

The effect of training on lactate transport capacity was studied in giant vesicles obtained with collagenase treatment of rat skeletal muscles. Marker enzyme analyses demonstrated that these vesicles are predominantly of sarcolemmal origin. Treadmill training induced significant adaptations in the capacity of rat skeletal muscles to transport lactate but swimming [low-intensity training, approximately 50% of maximal oxygen consumption (VO2 max)] did not. After 7 wk of moderate (90% of VO2max)- and high-intensity (112% of VO2max) interval treadmill training the carrier-mediated equilibrium exchange flux with 30 mM lactate was increased by 58 and 76%, respectively. During 5 wk of detraining the capacity to transport lactate decreased to near control level. It is concluded that physical training can increase the capacity to transport lactate in rat skeletal muscles and that the training intensity is of great importance. The adaptation appears to include both an increased number of transport proteins and a higher affinity of the individual transporters.

Effect of prior eccentric contractions on lactate/H+ transport in rat skeletal muscle

1998 ◽  
Vol 274 (3) ◽  
pp. E554-E559 ◽  
Author(s):  
Henriette Pilegaard ◽  
Sven Asp
Keyword(s):  
Skeletal Muscle ◽  
Buffer Capacity ◽  
Ph Regulation ◽  
Eccentric Contractions ◽  
Lactate Transport ◽  
Giant Vesicles ◽  
Muscle Lactate ◽  
Muscle Ph ◽  
Supramaximal Stimulation ◽  
Muscle Types

The effect of prior eccentric contractions on skeletal muscle lactate/H+transport was investigated in rats. Lactate transport was measured in sarcolemmal giant vesicles obtained from soleus and red (RG) and white gastrocnemii (WG) muscles 2 days after intense eccentric contractions (ECC) and from the corresponding contralateral control (CON) muscles. The physiochemical buffer capacity was determined in the three muscle types from both ECC and CON legs. Furthermore, the effect of prior eccentric contractions on release and muscle content of lactate and H+ during and after supramaximal stimulation was examined using the perfused rat hindlimb preparation. The lactate transport rate was lower ( P < 0.05) in vesicles obtained from ECC-WG (29%) and ECC-RG (13%) than in vesicles from the CON muscles. The physiochemical buffer capacity was reduced ( P < 0.05) in ECC-WG (13%) and ECC-RG (9%) compared with the corresponding CON muscles. There were only marginal effects on the soleus muscle. Muscle lactate concentrations and release of lactate during recovery from intense isometric contractions were lower ( P< 0.05) in ECC than in CON hindlimbs, indicating decreased anaerobic glycogenolysis. In conclusion, the sarcolemmal lactate/H+ transport capacity and the physiochemical buffer capacity were reduced in prior eccentrically stimulated WG and RG in rats, suggesting that muscle pH regulation may be impaired after unaccustomed eccentric exercise. In addition, the data indicate that the glycogenolytic potential is decreased in muscles exposed to prior eccentric contractions.

Lactate uptake by skeletal muscle sarcolemmal vesicles decreases after 4 wk of hindlimb unweighting in rats

1996 ◽  
Vol 80 (2) ◽  
pp. 416-421 ◽  
Author(s):  
H. Dubouchaud ◽  
P. Granier ◽  
J. Mercier ◽  
C. Le Peuch ◽  
C. Prefaut
Keyword(s):  
Skeletal Muscle ◽  
Citrate Synthase ◽  
Lactate Concentration ◽  
Myosin Heavy Chain Isoforms ◽  
Hindlimb Suspension ◽  
Control Group ◽  
Marker Enzyme ◽  
Transport Activity ◽  
Lactate Transport ◽  
Sarcolemmal Vesicles

We investigated the effects of 4 wk of hypodynamia on the rate of lactate transport in skeletal muscle sarcolemmal vesicles from control and hindlimb-suspended rats. Characterization of the sarcolemmal preparations was achieved with a marker enzyme (K+-p-nitrophenylphosphatase) and measurement of 1 mM [U-14C]lactate transport activity under zero-trans conditions with or without a pH gradient or the transport inhibitor alpha-hydroxycinnamate. Preparations from the two groups were not significantly different concerning yield and purification. Based on these results, we used this model to analyze the lactate transport activity after hypodynamia by tail suspension. Hindlimb suspension caused a shift from slow to fast myosin heavy chain isoforms in soleus muscles with a 40% decrease in the citrate synthase activity (from 35.3 +/- 3.7 to 21.4 +/- 2.1 mu mol x g-1 x min-1; P < 0.05). Lactate (1 mM) uptake in vesicles from the two groups was a function of time, and the rate after hindlimb suspension was significantly decreased in the suspended compared with the control group (2.25 +/- 0.44 and 3.50 +/- 0.26 nmol x min-1 x mg protein-1, respectively; P < 0.05). These differences were not observed for a higher lactate concentration (50 mM). These results suggest that the level of physical activity plays a role in the regulation of sarcolemmal lactate transport activity implicated in the exchanges of lactate between producing and utilizing cells, organs, and tissues, which are major ways of carbohydrate energy distribution in humans and others species.

Lactate transport studied in sarcolemmal giant vesicles from rat skeletal muscles: effect of denervation

1995 ◽  
Vol 269 (4) ◽  
pp. E679-E682 ◽  
Author(s):  
H. Pilegaard ◽  
C. Juel
Keyword(s):  
Skeletal Muscles ◽  
Transport Capacity ◽  
Lactate Transport ◽  
Giant Vesicles ◽  
Muscle Lactate ◽  
Ldh Activity ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Sarcolemmal Vesicles ◽  
White Gastrocnemius

The effect of denervation on lactate transport capacity was studied in giant sarcolemmal vesicles obtained from rat muscle. The rate of lactate transport was determined in soleus and red (RG) and white gastrocnemius (WG) after 1, 3, and 21 days of denervation and in the corresponding contralateral muscles. In addition, muscle lactate dehydrogenase (LDH) and succinate dehydrogenase (SDH) activities were determined. After 1, 3, and 21 days of denervation the rate of lactate transport was lower (P < 0.05) in WG (9, 11, and 36%), RG (15, 21, and 41%), and soleus (12, 24, and 50%) compared with the contralateral muscles. After 21 days of denervation LDH activity was 26, 25, and 34% and SDH activity 33, 25, and 27% lower (P < 0.05) in WG, RG, and soleus, respectively, compared with the contralateral muscles. In the control muscles the lactate transport capacity was 20 and 32% lower (P < 0.05) in WG than in RG and soleus, respectively. The present findings provide support that the sarcolemmal lactate carrier is a plastic system; the transport capacity in soleus, RG, and WG already declines after 1 day of denervation and is further reduced after 21 days of denervation. In addition, the data suggest that the lactate transport capacity in fast-twitch glycolytic fibers < fast-twitch oxidative-glycolytic fibers < slow-twitch oxidative fibers.

Insulin binding and glucose transport in rat skeletal muscle sarcolemmal vesicles

1985 ◽  
Vol 249 (4) ◽  
pp. E398-E408 ◽  
Author(s):  
G. K. Grimditch ◽  
R. J. Barnard ◽  
S. A. Kaplan ◽  
E. Sternlicht
Keyword(s):  
Skeletal Muscle ◽  
Glucose Transport ◽  
High Purity ◽  
Insulin Binding ◽  
Marker Enzyme ◽  
Transport Studies ◽  
Equilibrium Exchange ◽  
Scatchard Plots ◽  
Sarcolemmal Vesicles

A new method is described for isolation of sarcolemma (SL) from skeletal muscle of rats that produces vesicles of high purity and yield. There was a mean 59-fold purification (n = 22) of the SL marker enzyme K+-p-nitrophenylphosphatase. Specific activities of marker enzymes for sarcoplasmic reticulum and mitochondria were low, indicating minimal contamination. Despite the high purity and low contamination, a relatively high protein yield was achieved (0.43 +/- 0.03 mg/g wet wt, n = 25). Electron microscopy showed that the membranes were primarily vesicles. Specific 125I-insulin binding association constants derived from the high- and low-affinity portion of the Scatchard plots were 0.764 +/- 0.154 and 0.0096 +/- 0.0012 X 10(9) M-1, whereas the apparent number of receptors were 15.0 +/- 4.1 and 925 +/- 80 X 10(9) per mg of SL protein. Equilibrium exchange glucose transport studies at 37 degrees C indicated that the SL vesicles exhibited specific D-glucose transport which was responsive to in vivo insulin stimulation. We conclude that this isolation procedure, especially in light of the high purity and yield, provides a good and practical experimental model for studying insulin binding and glucose transport in skeletal muscle.

Which common NIRS variable reflects muscle estimated lactate threshold most closely?

2006 ◽  
Vol 31 (5) ◽  
pp. 612-620 ◽  
Author(s):  
Lixin Wang ◽  
Takahiro Yoshikawa ◽  
Taketaka Hara ◽  
Hayato Nakao ◽  
Takashi Suzuki ◽  
...  
Keyword(s):  
Lactate Threshold ◽  
Near Infrared ◽  
Ventilatory Threshold ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Oxygenation Index ◽  
Muscle Lactate ◽  
Tissue Oxygenation Index ◽  
The Mean ◽  
Tissue Hemoglobin

Various near-infrared spectroscopy (NIRS) variables have been used to estimate muscle lactate threshold (LT), but no study has determined which common NIRS variable best reflects muscle estimated LT. Establishing the inflection point of 2 regression lines for deoxyhaemoglobin (ΔHHbi.p.), oxyhaemoglobin (ΔO2Hbi.p.), and tissue oxygenation index (TOIi.p.), as well as for blood lactate concentration, we then investigated the relationships between NIRS variables and ventilatory threshold (VT), LT, or maximal tissue hemoglobin index (nTHImax) during incremental cycling exercise. ΔHHbi.p. and TOIi.p. could be determined for all 15 subjects, but ΔO2Hbi.p. was determined for only 11 subjects. The mean absolute values for the 2 measurable slopes of the 2 continuous linear regression lines exhibited increased changes in 3 NIRS variables. The workload and VO2 at ΔO2Hbi.p. and nTHImax were greater than those at VT, LT, ΔHHbi.p., and TOIi.p.. For workload and VO2, ΔHHbi.p. was correlated with VT and LT, whereas ΔO2Hbi.p. was correlated with nTHImax, and TOIi.p. with VT and nTHImax. These findings indicate that ΔO2Hb strongly corresponds with local perfusion, and TOI corresponds with both local perfusion and deoxygenation, but that ΔHHb can exactly determine deoxygenation changes and reflect O2 metabolic dynamics. The finding of strongest correlations between ΔHHb and VT or LT indicates that ΔHHb is the best variable for muscle LT estimation.

Contraction duration affects metabolic energy cost and fatigue in skeletal muscle

1998 ◽  
Vol 274 (3) ◽  
pp. E397-E402 ◽  
Author(s):  
Michael C. Hogan ◽  
Erica Ingham ◽  
S. Sadi Kurdak
Keyword(s):  
Skeletal Muscle ◽  
Short Duration ◽  
Energy Cost ◽  
Lactate Concentration ◽  
Metabolic Energy ◽  
Muscle Lactate ◽  
Contracting Muscle ◽  
Contraction Duration ◽  
Long Duration ◽  
The Difference

It has been suggested that during a skeletal muscle contraction the metabolic energy cost at the onset may be greater than the energy cost related to holding steady-state force. The purpose of the present study was to investigate the effect of contraction duration on the metabolic energy cost and fatigue process in fully perfused contracting muscle in situ. Canine gastrocnemius muscle ( n = 6) was isolated, and two contractile periods (3 min of isometric, tetanic contractions with 45-min rest between) were conducted by each muscle in a balanced order design. The two contractile periods had stimulation patterns that resulted in a 1:3 contraction-to-rest ratio, with the difference in the two contractile periods being in the duration of each contraction: short duration 0.25-s stimulation/0.75-s rest vs. long duration 1-s stimulation/3-s rest. These stimulation patterns resulted in the same total time of stimulation, number of stimulation pulses, and total time in contraction for each 3-min period. Muscle O2 uptake, the fall in developed force (fatigue), the O2 cost of developed force, and the estimated total energy cost (ATP utilization) of developed force were significantly greater ( P < 0.05) with contractions of short duration. Lactate efflux from the working muscle and muscle lactate concentration were significantly greater with contractions of short duration, such that the calculated energy derived from glycolysis was three times greater in this condition. These results demonstrate that contraction duration can significantly affect both the aerobic and anaerobic metabolic energy cost and fatigue in contracting muscle. In addition, it is likely that the greater rate of fatigue with more rapid contractions was a result of elevated glycolytic production of lactic acid.

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