title: Endurance training alters basal erythrocyte MCT-1 contents and affects the lactate distribution between plasma and red blood cells in T2DM men following maximal exercise.
abstract: Chronic elevated lactate levels are associated with insulin resistance in patients with type 2 diabetes mellitus (T2DM). Furthermore, lactacidosis plays a role in limiting physical performance. Erythrocytes, which take up lactate via monocarboxylate transporter (MCT) proteins, may help transport lactate within the blood from lactate-producing to lactate-consuming organs. This study investigates whether cycling endurance training (3 times/week for 3 months) alters the basal erythrocyte content of MCT-1, and whether it affects lactate distribution kinetics in the blood of T2DM men (n = 10, years = 61 ± 9, body mass index = 31 ± 3 kg/m(2)) following maximal exercise (WHO step-incremental cycle ergometer test). Immunohistochemical staining indicated that basal erythrocyte contents of MCT-1 protein were up-regulated (+90%, P = 0.011) post-training. Erythrocyte and plasma lactate increased from before acute exercise (= resting values) to physical exhaustion pre- as well as post-training (pre-training: +309%, P = 0.004; +360%, P < 0.001; post-training: +318%, P = 0.008; +300%, P < 0.001), and did not significantly decrease during 5 min recovery. The lactate ratio (erythrocytes:plasma) remained unchanged after acute exercise pre-training, but was significantly increased after 5 min recovery post-training (compared with the resting value) (+22%, P = 0.022). The results suggest an increased time-delayed influx of lactate into erythrocytes following an acute bout of exercise in endurance-trained diabetic men.
authors.affiliation: Department of Molecular and Cellular Sport Medicine, Institute of Cardiovascular Research and Sport Medicine, German Sport University Cologne, Am Sportpark Müngersdorf 6, 50933 Cologne, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Opitz
authors.forename: Edward
authors.initials: E
authors.lastname: Lenzen
authors.forename: Andreas
authors.initials: A
authors.lastname: Opiolka
authors.forename: Melanie
authors.initials: M
authors.lastname: Redmann
authors.forename: Martin
authors.initials: M
authors.lastname: Hellmich
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Bloch
authors.forename: Klara
authors.initials: K
authors.lastname: Brixius
authors.forename: Christian
authors.initials: C
authors.lastname: Brinkmann
mesh_terms: D015992:Body Mass Index; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism*; D015444:Exercise / Q000502:physiology; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology; D019344:Lactic Acid / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D027501:Monocarboxylic Acid Transporters / Q000378:metabolism*; D010807:Physical Endurance / Q000502:physiology*; D010949:Plasma / Q000378:metabolism*; D027981:Symporters / Q000378:metabolism*; D015854:Up-Regulation / Q000502:physiology; D000099233:Monocarboxylate Transport Protein 1
chemical_list: D019344:Lactic Acid; D027501:Monocarboxylic Acid Transporters; D027981:Symporters; D000099233:Monocarboxylate Transport Protein 1
keywords: RBC; diabète de type 2; monocarboxylate transporter; transporteur de monocarboxylate; type 2 diabetes; érythrocytes