Muscle lactate transport studied in sarcolemmal giant vesicles: dependence on fibre type and age

1991 ◽  
Vol 143 (4) ◽  
pp. 361-366 ◽  
Author(s):  
C. JUEL ◽  
A. HONIG ◽  
H. PILEGAARD
Keyword(s):  
Fibre Type ◽  
Lactate Transport ◽  
Giant Vesicles ◽  
Muscle Lactate

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.

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 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.

Effects of Exercise on Lactate Transport Into Mouse Skeletal Muscles

1994 ◽  
Vol 19 (3) ◽  
pp. 275-285 ◽  
Author(s):  
Arend Bonen ◽  
Karl J. A. McCullagh
Keyword(s):  
Skeletal Muscle ◽  
Key Words ◽  
Muscle Glycogen ◽  
Skeletal Muscles ◽  
Treadmill Exercise ◽  
Lactate Transport ◽  
Muscle Lactate ◽  
Slow Twitch ◽  
Fast Twitch

Skeletal muscle lactate transport was investigated in vitro in isolated fast-twitch (EDL) and slow-twitch soleus (Sol) skeletal muscles from control and exercised mice. Exercise (23 m/min, 8% grade) reduced muscle glycogen by 37% in EDL (p < 0.05) and by 35% in Sol muscles (p < 0.05). Lactate transport measurements (45 sec) were performed after 60 min of exercise in intact EDL and Sol muscles in vitro, at differing pH (6.5 and 7.4) and differing lactate concentrations (4 and 30 mM). Lactate transport was observed to be greater in Sol than in EDL (p < 0.05). In the exercised muscles there was a small but significant increase in lactate transport (p < 0.05). Lactate transport was greater when exogenous lactate concentrations were greater (p < 0.05) and more rapid at the lower pH (p < 0.05). These studies demonstrated that lactate transport was increased with exercise. Key words: soleus, EDL, treadmill exercise

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.

Lactate transport studied in sarcolemmal giant vesicles from human muscle biopsies: relation to training status

1994 ◽  
Vol 77 (4) ◽  
pp. 1858-1862 ◽  
Author(s):  
H. Pilegaard ◽  
J. Bangsbo ◽  
E. A. Richter ◽  
C. Juel
Keyword(s):  
Fiber Type ◽  
Vastus Lateralis ◽  
High Volume ◽  
Type I ◽  
Training Status ◽  
Transport Capacity ◽  
Lactate Transport ◽  
Giant Vesicles ◽  
Trained Subjects ◽  
Muscle Biopsies

The present study examined sarcolemmal lactate transport capacity in humans of widely different training status. Muscle biopsies were obtained from m. vastus lateralis in 39 subjects divided into untrained (n = 13), trained (n = 7), and athlete [sprint runners (n = 2), endurance runners (n = 5), triathletes (n = 3), and road (n = 6) and track (n = 3) bicyclists] groups. From the biopsy sample giant vesicles were produced with collagenase treatment to determine the sarcolemmal lactate transport capacity, and histochemical analyses were made. The athletes had a higher capacity to transport lactate than the untrained and trained subjects (P < 0.01). Within the group of athletes, the bicyclists had a higher lactate transport capacity than the runners (P < 0.05), whereas there was no difference among trained subjects, runners, and triathletes. The lactate transport capacity was related to the occurrence of type I muscle fibers (r = 0.48, P < 0.01). The present results suggest that the capacity to transport lactate is higher in athletes than in untrained and less trained subjects. It might indicate that lactate transport capacity in human skeletal muscle can be changed by a high volume of training including frequent high-intensity sessions. In addition, sarcolemmal lactate transport capacity appears to be related to the fiber type distribution of a muscle.

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