Effect of food restriction on lactate sarcolemmal transport.
The objective of this study was to investigate the effects of 6 weeks of food restriction (FR) on sarcolemmal lactate transport in rats. The daily food consumption of rats was monitored for 10 days, after which they were assigned to either a control group (CTL, n = 7) that consumed food ad libitum or an FR group (n = 7) that received a daily ration equal to 60% of their predetermined baseline food intake. After the 6-week period, we observed in red gastrocnemius (RG) a fall of 48% in glycogen content (P <.01) and a reduction in glutathione peroxidase activity (P <.05), confirming that the FR program was well executed. FR resulted in a reduction in muscle lactate (P <.05) and liver glycogen contents (P <.01). Moreover, hyperlactatemia was noted in the FR group: 1.77 +/- 0.24 versus 2.67 +/- 0.29 mmol/L (P <.05). Lactate transport capacity was significantly increased (P <.05) in FR rats, although monocarboxylate transporter isoforms (MCT1 and MCT4) did not change significantly. We conclude that FR alters sarcolemmal lactate transport activity without affecting MCT1 and MCT4 expression.
Lambert
K
K
Département de Physiologie des Interactions, Institut de Biologie, Boulevard Henri IV, Montpellier, France.
Py
G
G
Eydoux
N
N
Matecki
S
S
Ramonatxo
M
M
Préfaut
C
C
Mercier
J
J
D000818:Animals; D001692:Biological Transport; D002950:Citrate (si)-Synthase / Q000378:metabolism; D005508:Food Deprivation; D005979:Glutathione Peroxidase / Q000378:metabolism; D006003:Glycogen / Q000032:analysis; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D019344:Lactic Acid / Q000097:blood / Q000378:metabolism*; D008099:Liver / Q000737:chemistry; D008297:Male; D027501:Monocarboxylic Acid Transporters / Q000032:analysis; D009124:Muscle Proteins / Q000032:analysis; D018482:Muscle, Skeletal / Q000737:chemistry / Q000378:metabolism; D010732:Phosphofructokinase-1 / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012508:Sarcolemma / Q000378:metabolism*; D027981:Symporters / Q000032:analysis; D000099233:Monocarboxylate Transport Protein 1
D002950:Citrate (si)-Synthase; D005979:Glutathione Peroxidase; D006003:Glycogen; D007770:L-Lactate Dehydrogenase; D019344:Lactic Acid; D027501:Monocarboxylic Acid Transporters; D009124:Muscle Proteins; D010732:Phosphofructokinase-1; D027981:Symporters; D000099233:Monocarboxylate Transport Protein 1; C516342:Slc16a3 protein, rat