title: Lactate-transport activity in RBCs of trained and untrained individuals from four racing species.
abstract: In red blood cells (RBC) of horses, both lactate-transport activity and lactate accumulation during races vary interindividually. To study whether similar variation in lactate transport is apparent also in RBCs of other racing species, blood samples were collected from 21 reindeer, 40 horses, 31 humans, and 38 dogs. Total lactate-transport activity was measured at 10 and 30 mM concentrations, and the roles of the monocarboxylate-transporter (MCT) and the inorganic anion-exchange transporter (band-3 protein) were studied with inhibitors. In the reindeer and in one-third of the horses, lactate transport was low and mediated mainly by band-3 protein and nonionic diffusion. In the humans, dogs, and the remaining two-thirds of the horses, lactate transport was high and MCT was the main transporter. No correlation existed between MCT activity and the athleticism of the species. In the horses and humans, training had no effect on lactate transport, but in the reindeer and sled dogs, training increased total lactate transport. These results show that among the racing species studied, only in horses was the distribution of lactate-transport activity bimodal, and the possible connection between RBC lactate and performance capacity, especially in this species, warrants further studies.
authors.affiliation: Department of Basic Veterinary Sciences, University of Helsinki, FIN-00014 Helsinki, Finland. leena.vaihkonen@pp.phnet.fi
authors.forename: L K
authors.initials: LK
authors.lastname: Väihkönen
authors.forename: O J
authors.initials: OJ
authors.lastname: Heinonen
authors.forename: S
authors.initials: S
authors.lastname: Hyyppä
authors.forename: M
authors.initials: M
authors.lastname: Nieminen
authors.forename: A R
authors.initials: AR
authors.lastname: Pösö
mesh_terms: D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000494:pharmacology; D000293:Adolescent; D000328:Adult; D000818:Animals; D001457:Anion Exchange Protein 1, Erythrocyte / Q000378:metabolism; D001692:Biological Transport / Q000187:drug effects / Q000502:physiology; D002352:Carrier Proteins / Q000378:metabolism; D003373:Coumaric Acids / Q000494:pharmacology; D003670:Deer; D004285:Dogs; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D006736:Horses; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D008875:Middle Aged; D027501:Monocarboxylic Acid Transporters; D005082:Physical Exertion / Q000502:physiology*; D012420:Running / Q000502:physiology*; D013045:Species Specificity
chemical_list: D001457:Anion Exchange Protein 1, Erythrocyte; D002352:Carrier Proteins; D003373:Coumaric Acids; D027501:Monocarboxylic Acid Transporters; C007175:alpha-cyano-4-hydroxycinnamate; D019344:Lactic Acid; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid