EurekaMag.com logo
+ Site Statistics
References:
53,214,146
Abstracts:
29,074,682
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Lactate utilization by an in situ perfused trout heart effects of workload and blockers of lactate transport



Lactate utilization by an in situ perfused trout heart effects of workload and blockers of lactate transport



Journal of Experimental Biology 155: 357-374



Lactate utilization was studied in an in situ perfused trout heart preparation that was capable of performing at levels similar to in vivo maximum cardiac performance. Hearts were perfused with modified Cortland saline containing 0.5 mmol l-1 iodoacetic acid (to block endogenous glycolysis) and varying amounts of lactate (1 or 10 mmol l-1). We confirmed previous observations that lactate utilization is limited by substrate availability. However, contrary to previous observations, exogenous fuel availability did not limit cardiac performance, even at the high workload. Furthermore, when plentiful (i.e. 10 mmol l-1), exogenous lactate was preferred over endogenous fuel and was able to supply the heart's energy requirements at both the low and high workloads. Pyruvate at 10-fold greater concentration, had no apparent effect on lactate utilization at the high workload. .alpha.-Cyano-4-hydroxycinnamate (.alpha.-CIN) (2.5 mmol l-1) proved to be an unsuitable probe of lactate transport in the trout heart as it caused a reduction in both lactate utilization and cardiac performance. However, addition of 20 .mu.mol l-1 isobutyl carbonyl lactyl anhydride or 100 .mu.mol l-1 4-acetamido-4'-isothiocyanostilbene-2,2'-disulphonic acid (putative lactate transport blockers) to the perfusate virtually abolished lactate oxidation at the high workload without affecting cardiac performance. These observations suggest that lactate uptake by the in situ perfused trout heart is carrier-mediated.

(PDF 0-2 workdays service: $29.90)

Accession: 007504182

Download citation: RISBibTeXText



Related references

Lactate release and uptake in hepatoma 7288CTC perfused in situ with L-[(U)-14C]lactate or D-[(U)-14C]glucose. Metabolism: Clinical and Experimental 43(12): 1488-1497, 1994

Lactate release and uptake in hepatoma 7288CTC perfused in situ with L- -14C lactate or D- -14C glucose. Metabolism Clinical & Experimental 43(12): 1488-1497, 1994

Lactate release and uptake in hepatoma 7288CTC perfused in situ with L- lactate. FASEB Journal 8(4-5): A811, 1994

Effectiveness of xylose utilization for high yield production of lactate-enriched P(lactate-co-3-hydroxybutyrate) using a lactate-overproducing strain of Escherichia coli and an evolved lactate-polymerizing enzyme. Metabolic Engineering 15: 159-166, 2013

Rates of glucose and lactate oxidation by the perfused isolated trout (Salvelinus fontinalis) heart. Canadian Journal of Zoology, 589: 1708-1711, 1980

Evidence for a lactate transport system in the sarcolemmal membrane of the perfused rabbit heart kinetics of unidirectional influx carrier specificity and effects of glucagon. Biochimica et Biophysica Acta 819(2): 241-248, 1985

Supersensitivity to isoprenaline evoked in cultured neonatal rat heart cells cnrhc by l dextro lactate dependence on lactate utilization. Journal of Molecular & Cellular Cardiology 19(SUPPL 3): S109, 1987

L-Lactate transport into rat heart mitochondria and reconstruction of the L-lactate/pyruvate shuttle. Biochemical Journal 364(Pt 1): 101-104, 2002

Lactate transport in perfused skeletal muscle effects of flow rate contraction and transport inhibitors. FASEB Journal 5(6): A1725, 1991

Non-utilization of succinate and metabolism of lactate as non-invasive criteria of viability in the isolated perfused canine heart at 4 degrees C. Experientia 30(3): 236-237, 1974

The effect of preexercise lactate duration of break and the increase of workload on the lactate turnpoint. Deutsche Zeitschrift fuer Sportmedizin 42(6): 248, 250-252, 255, 258, 260, 262-263, 1991

Effects of flow and contraction on lactate transport in the perfused rat hindlimb. American Journal of Physiology 267(1 Pt 1): E7-13, 1994