Human muscle lactate transport can be studied in sarcolemmal giant vesicles made from needle-biopsies

1991 ◽  
Vol 142 (1) ◽  
pp. 133-134 ◽  
Author(s):  
C. JUEL
Keyword(s):  
Human Muscle ◽  
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.

Propranolol enhances adenine nucleotide degradation in human muscle during exercise

1988 ◽  
Vol 65 (6) ◽  
pp. 2478-2483 ◽  
Author(s):  
S. Broberg ◽  
A. Katz ◽  
K. Sahlin
Keyword(s):  
Adenine Nucleotide ◽  
Human Muscle ◽  
Similar Increase ◽  
Intense Exercise ◽  
Muscle Lactate ◽  
Healthy Men ◽  
Beta Adrenoceptor ◽  
O2 Transport ◽  
Nucleotide Degradation ◽  
Hexose Phosphates

Eight healthy men cycled to exhaustion [4.1 +/- 0.3 (SE) min] during beta-adrenoceptor blockade (beta B) with propranolol. The exercise was repeated on another day with the same power output and duration but without propranolol (control). The total adenine nucleotide (TAN) content in muscle (quadriceps femoris) decreased during exercise, and the decrease was more pronounced during beta B (delta TAN = 4.8 +/- 1.0 mmol/kg dry wt) than during control (delta TAN = 2.8 +/- 0.9; P less than 0.01, beta B vs. control). The decrease in TAN corresponded with a similar increase in inosine 5'-monophosphate (IMP). The increase in IMP was more pronounced during beta B (delta IMP = 5.1 +/- 1.2 mmol/kg dry wt) than during control (delta IMP = 2.8 +/- 0.7; P less than 0.05, beta B vs. control). Similarly, the increase in the content of NH3 in muscle was twice as high during beta B vs. control (P less than 0.01). The increase in muscle lactate and the decrease in phosphocreatine during exercise were similar between treatments, but postexercise hexose phosphates were approximately twofold higher (P less than 0.05) during control than during beta B. It is concluded that beta B enhances the degradation of TAN and the production of NH3 and IMP in muscle during intense exercise. This indicates that the imbalance between the rates of utilization and resynthesis of ATP is more pronounced during beta B possibly because of a decreased O2 transport to the contracting muscle and a diminished activation of glycolysis by the hexose phosphates.(ABSTRACT TRUNCATED AT 250 WORDS)

Exercise-induced increase in glucose transport, GLUT-4, and VAMP-2 in plasma membrane from human muscle

1996 ◽  
Vol 270 (1) ◽  
pp. E197-E201 ◽  
Author(s):  
S. Kristiansen ◽  
M. Hargreaves ◽  
E. A. Richter
Keyword(s):  
Plasma Membrane ◽  
Protein Content ◽  
Glucose Transport ◽  
Fold Increase ◽  
Muscle Contractions ◽  
Human Muscle ◽  
Intrinsic Activity ◽  
Giant Vesicles ◽  
Glut 4 ◽  
Exercise Induced

A major effect of muscle contractions is an increase in sarcolemmal glucose transport. We have used a recently developed technique to produce sarcolemmal giant vesicles from human muscle biopsy samples obtained before and after exercise. Six men exercised for 10 min at 50% maximal O2 uptake (Vo2max) and then to fatigue at 100% Vo2max (5.7 +/- 0.2 min). Vesicle glucose transport at 5 mM increased from 3.3 +/- 0.6 pmol.microgram-1.min-1 at rest to 6.6 +/- 1.0 pmol.microgram-1.min-1 at fatigue (mean +/- SE, n = 6, P < 0.05). This increase in glucose transport was associated with a 1.6-fold increase in vesicle GLUT-4 protein content. Glucose transport normalized to GLUT-4 protein content also increased with exercise, suggesting increased intrinsic activity of GLUT-4. Furthermore, exercise resulted in a 1.4-fold increase in sarcolemmal vesicle-associated membrane protein (VAMP-2) content, suggesting that muscle contractions may induce trafficking of GLUT-4-containing vesicles via a mechanism similar to neurotransmitter release. Our results demonstrate for the first time exercise-induced translocation of GLUT-4 and VAMP-2 to the plasma membrane of human muscle and increased sarcolemmal glucose transport.

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

Distribution of monocarboxylate transporters MCT1-MCT8 in rat tissues and human skeletal muscle

2006 ◽  
Vol 31 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Arend Bonen ◽  
Miriam Heynen ◽  
Hideo Hatta
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Ketone Bodies ◽  
Human Muscle ◽  
Transport Kinetics ◽  
Monocarboxylate Transporters ◽  
Rat Tissues ◽  
Muscle Lactate ◽  
Metabolic Role ◽  
Lactate And Pyruvate

In the past decade, a family of monocarboxylate transporters (MCTs) have been identified that can potentially transport lactate, pyruvate, ketone bodies, and branched-chain ketoacids. Currently, 14 such MCTs are known. However, many orphan transporters exist that have transport capacities that remain to be determined. In addition, the tissue distribution of many of these MCTs is not well defined. Such a cataloging can, at times, begin to suggest the metabolic role of a particular MCT. Recently, a number of antibodies against selected MCTs (MCT1, -2, -4, and -5 to -8) have become commercially available. Therefore, we examined the protein expression of these MCTs in a large number of rat tissues (heart, skeletal muscle, skin, brain, testes, vas deferens, adipose tissue, liver, kidney, spleen, and pancreas), as well as in human skeletal muscle. Unexpectedly, many tissues coexpressed 4-5 MCTs. In particular, in rat skeletal muscle MCT1, MCT2, MCT4, MCT5, and MCT6 were observed. In human muscle, these same MCTs were present. We also observed a pronounced MCT7 signal in human muscle, whereas a very faint signal occurred for MCT8. In rat heart, which is an important metabolic sink for lactate, we confirmed that MCT1 and -2 were expressed. In addition, MCT6 and -8 were also prominently expressed in this tissue, although it is known that MCT8 does not transport aromatic amino acids or lactate. This catalog of MCTs in skeletal muscle and other tissues has revealed an unexpected complexity of coexpression, which makes it difficult to associate changes in monocarboxylate transport with the expression of a particular MCT. The differences in transport kinetics for lactate and pyruvate are only known for MCT1, -2 and -4. Transport kinetics remain to be established for many other MCTs. In conclusion, this study suggests that in skeletal muscle, as well as other tissues, lactate and pyruvate transport rates may not only involve MCT1 and -4, as other monocarboxylate transporters are also expressed in rat (MCT2, -5, -6) and human skeletal muscle (MCT2, -5, -6, -7).Key words: muscle, lactate, pyruvate, human, rat.

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.

Sign in / Sign up

Export Citation Format

Share Document