Sarcolemmal ion currents and sarcoplasmic reticulum Ca2+ content in ventricular myocytes from the cold stenothermic fish, the burbot (Lota lota)
The burbot (Lota lota) is a cold stenothermic fish species whose heart is adapted to function in the cold. In this study we use whole-cell voltage-clamp techniques to characterize the electrophysiological properties of burbot ventricular myocytes and to test the hypothesis that changes in membrane c...
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2006
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Online Access: | https://research.manchester.ac.uk/en/publications/a7e7770e-b7dc-4dbc-b928-f203cd2067f3 https://doi.org/10.1242/jeb.02321 |
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ftumanchesterpub:oai:pure.atira.dk:publications/a7e7770e-b7dc-4dbc-b928-f203cd2067f3 2024-06-23T07:51:52+00:00 Sarcolemmal ion currents and sarcoplasmic reticulum Ca2+ content in ventricular myocytes from the cold stenothermic fish, the burbot (Lota lota) Shiels, Holly A. Paajanen, Vesa Vornanen, Matti 2006-08 https://research.manchester.ac.uk/en/publications/a7e7770e-b7dc-4dbc-b928-f203cd2067f3 https://doi.org/10.1242/jeb.02321 eng eng https://research.manchester.ac.uk/en/publications/a7e7770e-b7dc-4dbc-b928-f203cd2067f3 info:eu-repo/semantics/closedAccess Shiels , H A , Paajanen , V & Vornanen , M 2006 , ' Sarcolemmal ion currents and sarcoplasmic reticulum Ca2+ content in ventricular myocytes from the cold stenothermic fish, the burbot (Lota lota) ' , Journal of Experimental Biology , vol. 209 , no. 16 , pp. 3091-3100 . https://doi.org/10.1242/jeb.02321 Action potential Burbot Caffeine Fish heart I K1 ICa IKr Isoprenaline K+ channel L-type Ca 2+ channel Lota lota Na+-Ca2+ exchange Sarcoplasmic reticulum (SR) Temperature article 2006 ftumanchesterpub https://doi.org/10.1242/jeb.02321 2024-06-04T00:39:40Z The burbot (Lota lota) is a cold stenothermic fish species whose heart is adapted to function in the cold. In this study we use whole-cell voltage-clamp techniques to characterize the electrophysiological properties of burbot ventricular myocytes and to test the hypothesis that changes in membrane currents and intracellular Ca2+ cycling associated cold-acclimation in other fish species are routine for stenothermic cold-adapted species. Experiments were performed at 4°C, which is the body temperature of burbot for most of the year, and after myocytes were acutely warmed to 11°C, which is in the upper range of temperatures experienced by burbot in nature. Results on K+ channels support our hypothesis as the relative density of K-channel conductances in the burbot heart are similar to those found for cold-acclimated cold-active fish species. IK1 conductance was small (39.2±5.4 pS pF-1 at 4°C and 71.4±1.7 pS pF -1 at 11°C) and IKr was large (199±27 pS pF-1 at 4°C and 320.3±8 pS pF-1 at 11°C) in burbot ventricular myocytes. We found high Na+-Ca2+ exchange (NCX) activity (35.9±6.3 pS pF-1 at 4°C and 58.6±8.4 pS pF-1 at 11°C between -40 and 20 mV), suggesting that it may be the primary pathway for sarcolemmal (SL) Ca 2+ influx in this species. In contrast, the density (ICa, 0.81±0.13 pA pF-1 at 4°C, and 1.35±0.18 pA pF -1 at 11°C) and the charge (QCa, 0.24±0.043 pC pF-1 at 4°C and 0.21±0.034 pC pF-1 at 11°C) carried by the L-type Ca2+ current was small. Our results on sarcolemmal ion currents in burbot ventricular myocytes suggest that cold stenothermy and compensative cold-acclimation involve many of the same subcellular adaptations that culminate in enhanced excitability in the cold. Article in Journal/Newspaper Burbot Lota lota lota The University of Manchester: Research Explorer Journal of Experimental Biology 209 16 3091 3100 |
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Open Polar |
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The University of Manchester: Research Explorer |
op_collection_id |
ftumanchesterpub |
language |
English |
topic |
Action potential Burbot Caffeine Fish heart I K1 ICa IKr Isoprenaline K+ channel L-type Ca 2+ channel Lota lota Na+-Ca2+ exchange Sarcoplasmic reticulum (SR) Temperature |
spellingShingle |
Action potential Burbot Caffeine Fish heart I K1 ICa IKr Isoprenaline K+ channel L-type Ca 2+ channel Lota lota Na+-Ca2+ exchange Sarcoplasmic reticulum (SR) Temperature Shiels, Holly A. Paajanen, Vesa Vornanen, Matti Sarcolemmal ion currents and sarcoplasmic reticulum Ca2+ content in ventricular myocytes from the cold stenothermic fish, the burbot (Lota lota) |
topic_facet |
Action potential Burbot Caffeine Fish heart I K1 ICa IKr Isoprenaline K+ channel L-type Ca 2+ channel Lota lota Na+-Ca2+ exchange Sarcoplasmic reticulum (SR) Temperature |
description |
The burbot (Lota lota) is a cold stenothermic fish species whose heart is adapted to function in the cold. In this study we use whole-cell voltage-clamp techniques to characterize the electrophysiological properties of burbot ventricular myocytes and to test the hypothesis that changes in membrane currents and intracellular Ca2+ cycling associated cold-acclimation in other fish species are routine for stenothermic cold-adapted species. Experiments were performed at 4°C, which is the body temperature of burbot for most of the year, and after myocytes were acutely warmed to 11°C, which is in the upper range of temperatures experienced by burbot in nature. Results on K+ channels support our hypothesis as the relative density of K-channel conductances in the burbot heart are similar to those found for cold-acclimated cold-active fish species. IK1 conductance was small (39.2±5.4 pS pF-1 at 4°C and 71.4±1.7 pS pF -1 at 11°C) and IKr was large (199±27 pS pF-1 at 4°C and 320.3±8 pS pF-1 at 11°C) in burbot ventricular myocytes. We found high Na+-Ca2+ exchange (NCX) activity (35.9±6.3 pS pF-1 at 4°C and 58.6±8.4 pS pF-1 at 11°C between -40 and 20 mV), suggesting that it may be the primary pathway for sarcolemmal (SL) Ca 2+ influx in this species. In contrast, the density (ICa, 0.81±0.13 pA pF-1 at 4°C, and 1.35±0.18 pA pF -1 at 11°C) and the charge (QCa, 0.24±0.043 pC pF-1 at 4°C and 0.21±0.034 pC pF-1 at 11°C) carried by the L-type Ca2+ current was small. Our results on sarcolemmal ion currents in burbot ventricular myocytes suggest that cold stenothermy and compensative cold-acclimation involve many of the same subcellular adaptations that culminate in enhanced excitability in the cold. |
format |
Article in Journal/Newspaper |
author |
Shiels, Holly A. Paajanen, Vesa Vornanen, Matti |
author_facet |
Shiels, Holly A. Paajanen, Vesa Vornanen, Matti |
author_sort |
Shiels, Holly A. |
title |
Sarcolemmal ion currents and sarcoplasmic reticulum Ca2+ content in ventricular myocytes from the cold stenothermic fish, the burbot (Lota lota) |
title_short |
Sarcolemmal ion currents and sarcoplasmic reticulum Ca2+ content in ventricular myocytes from the cold stenothermic fish, the burbot (Lota lota) |
title_full |
Sarcolemmal ion currents and sarcoplasmic reticulum Ca2+ content in ventricular myocytes from the cold stenothermic fish, the burbot (Lota lota) |
title_fullStr |
Sarcolemmal ion currents and sarcoplasmic reticulum Ca2+ content in ventricular myocytes from the cold stenothermic fish, the burbot (Lota lota) |
title_full_unstemmed |
Sarcolemmal ion currents and sarcoplasmic reticulum Ca2+ content in ventricular myocytes from the cold stenothermic fish, the burbot (Lota lota) |
title_sort |
sarcolemmal ion currents and sarcoplasmic reticulum ca2+ content in ventricular myocytes from the cold stenothermic fish, the burbot (lota lota) |
publishDate |
2006 |
url |
https://research.manchester.ac.uk/en/publications/a7e7770e-b7dc-4dbc-b928-f203cd2067f3 https://doi.org/10.1242/jeb.02321 |
genre |
Burbot Lota lota lota |
genre_facet |
Burbot Lota lota lota |
op_source |
Shiels , H A , Paajanen , V & Vornanen , M 2006 , ' Sarcolemmal ion currents and sarcoplasmic reticulum Ca2+ content in ventricular myocytes from the cold stenothermic fish, the burbot (Lota lota) ' , Journal of Experimental Biology , vol. 209 , no. 16 , pp. 3091-3100 . https://doi.org/10.1242/jeb.02321 |
op_relation |
https://research.manchester.ac.uk/en/publications/a7e7770e-b7dc-4dbc-b928-f203cd2067f3 |
op_rights |
info:eu-repo/semantics/closedAccess |
op_doi |
https://doi.org/10.1242/jeb.02321 |
container_title |
Journal of Experimental Biology |
container_volume |
209 |
container_issue |
16 |
container_start_page |
3091 |
op_container_end_page |
3100 |
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1802643007750537216 |