Temperature-related differences in the calcium transient between Atlantic cod (Gadus morhua) and steelhead trout (Oncorhynchus mykiss) cardiomyocytes

The Atlantic cod, Gadus morhua, differs from many teleosts in that its heart does not respond to adrenergic stimulation, and is more capable of maintaining function during acute temperature changes. To examine if differences in intracellular calcium mobilization are associated with these atypical re...

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Main Author: Pellowe, Sarita D.
Format: Thesis
Language:English
Published: Memorial University of Newfoundland 2015
Subjects:
Online Access:https://research.library.mun.ca/11956/
https://research.library.mun.ca/11956/1/thesis.pdf
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spelling ftmemorialuniv:oai:research.library.mun.ca:11956 2023-10-01T03:54:31+02:00 Temperature-related differences in the calcium transient between Atlantic cod (Gadus morhua) and steelhead trout (Oncorhynchus mykiss) cardiomyocytes Pellowe, Sarita D. 2015-09 application/pdf https://research.library.mun.ca/11956/ https://research.library.mun.ca/11956/1/thesis.pdf en eng Memorial University of Newfoundland https://research.library.mun.ca/11956/1/thesis.pdf Pellowe, Sarita D. <https://research.library.mun.ca/view/creator_az/Pellowe=3ASarita_D=2E=3A=3A.html> (2015) Temperature-related differences in the calcium transient between Atlantic cod (Gadus morhua) and steelhead trout (Oncorhynchus mykiss) cardiomyocytes. Masters thesis, Memorial University of Newfoundland. thesis_license Thesis NonPeerReviewed 2015 ftmemorialuniv 2023-09-03T06:48:31Z The Atlantic cod, Gadus morhua, differs from many teleosts in that its heart does not respond to adrenergic stimulation, and is more capable of maintaining function during acute temperature changes. To examine if differences in intracellular calcium mobilization are associated with these atypical responses, confocal microscopy was used to study the calcium handling of cardiac cells from Atlantic cod vs. steelhead trout at their acclimation temperature (10ºC), or subjected to acute temperature changes (to 4 and 16ºC), while being stimulated across a range of frequencies (10 – 110 min⁻¹). In addition, cells were tested with and without tonic (10 nM) levels of adrenaline at 10ºC, and pharmacological blockers were used to study the relative contributions of the L-type Ca²⁺ channel, sarcoplasmic reticulum and Na+/Ca²⁺ exchanger to the Ca²⁺ transient. Consistent with previous in vitro and in situ studies, there were few significant effects of adrenaline on the Ca²⁺ transient of cod cardiomyocytes, yet adrenaline had significant positive inotropic effects on trout cardiomyocytes. At 10ºC, peak Ca²⁺ (F/F₀) only differed between the two species at low stimulation frequencies (10, 30 min-1), with trout F/F₀ 25-35% higher. In contrast, the time to peak Ca²⁺ and the time to half relaxation were both shorter (by 10 – 35% across frequencies) in cod. Acute temperature changes caused a shift in the Ca²⁺ - frequency relationship in both species, with F/F₀ values higher for trout at low frequencies (< 70 min⁻¹) at 4ºC, whereas this parameter was greater at all frequencies except 10 min⁻¹ in cod at 16ºC. Unfortunately, these experiments did not highlight clear species differences in the relative contributions of the L-type Ca²⁺ channels, sarcoplasmic reticulum and Na+/Ca²⁺ exchange to the Ca²⁺ transient. Thesis atlantic cod Gadus morhua Memorial University of Newfoundland: Research Repository
institution Open Polar
collection Memorial University of Newfoundland: Research Repository
op_collection_id ftmemorialuniv
language English
description The Atlantic cod, Gadus morhua, differs from many teleosts in that its heart does not respond to adrenergic stimulation, and is more capable of maintaining function during acute temperature changes. To examine if differences in intracellular calcium mobilization are associated with these atypical responses, confocal microscopy was used to study the calcium handling of cardiac cells from Atlantic cod vs. steelhead trout at their acclimation temperature (10ºC), or subjected to acute temperature changes (to 4 and 16ºC), while being stimulated across a range of frequencies (10 – 110 min⁻¹). In addition, cells were tested with and without tonic (10 nM) levels of adrenaline at 10ºC, and pharmacological blockers were used to study the relative contributions of the L-type Ca²⁺ channel, sarcoplasmic reticulum and Na+/Ca²⁺ exchanger to the Ca²⁺ transient. Consistent with previous in vitro and in situ studies, there were few significant effects of adrenaline on the Ca²⁺ transient of cod cardiomyocytes, yet adrenaline had significant positive inotropic effects on trout cardiomyocytes. At 10ºC, peak Ca²⁺ (F/F₀) only differed between the two species at low stimulation frequencies (10, 30 min-1), with trout F/F₀ 25-35% higher. In contrast, the time to peak Ca²⁺ and the time to half relaxation were both shorter (by 10 – 35% across frequencies) in cod. Acute temperature changes caused a shift in the Ca²⁺ - frequency relationship in both species, with F/F₀ values higher for trout at low frequencies (< 70 min⁻¹) at 4ºC, whereas this parameter was greater at all frequencies except 10 min⁻¹ in cod at 16ºC. Unfortunately, these experiments did not highlight clear species differences in the relative contributions of the L-type Ca²⁺ channels, sarcoplasmic reticulum and Na+/Ca²⁺ exchange to the Ca²⁺ transient.
format Thesis
author Pellowe, Sarita D.
spellingShingle Pellowe, Sarita D.
Temperature-related differences in the calcium transient between Atlantic cod (Gadus morhua) and steelhead trout (Oncorhynchus mykiss) cardiomyocytes
author_facet Pellowe, Sarita D.
author_sort Pellowe, Sarita D.
title Temperature-related differences in the calcium transient between Atlantic cod (Gadus morhua) and steelhead trout (Oncorhynchus mykiss) cardiomyocytes
title_short Temperature-related differences in the calcium transient between Atlantic cod (Gadus morhua) and steelhead trout (Oncorhynchus mykiss) cardiomyocytes
title_full Temperature-related differences in the calcium transient between Atlantic cod (Gadus morhua) and steelhead trout (Oncorhynchus mykiss) cardiomyocytes
title_fullStr Temperature-related differences in the calcium transient between Atlantic cod (Gadus morhua) and steelhead trout (Oncorhynchus mykiss) cardiomyocytes
title_full_unstemmed Temperature-related differences in the calcium transient between Atlantic cod (Gadus morhua) and steelhead trout (Oncorhynchus mykiss) cardiomyocytes
title_sort temperature-related differences in the calcium transient between atlantic cod (gadus morhua) and steelhead trout (oncorhynchus mykiss) cardiomyocytes
publisher Memorial University of Newfoundland
publishDate 2015
url https://research.library.mun.ca/11956/
https://research.library.mun.ca/11956/1/thesis.pdf
genre atlantic cod
Gadus morhua
genre_facet atlantic cod
Gadus morhua
op_relation https://research.library.mun.ca/11956/1/thesis.pdf
Pellowe, Sarita D. <https://research.library.mun.ca/view/creator_az/Pellowe=3ASarita_D=2E=3A=3A.html> (2015) Temperature-related differences in the calcium transient between Atlantic cod (Gadus morhua) and steelhead trout (Oncorhynchus mykiss) cardiomyocytes. Masters thesis, Memorial University of Newfoundland.
op_rights thesis_license
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