Frequency-dependent changes in calcium cycling and contractile activation in SERCA2a transgenic mice

Objective: This study was undertaken to investigate the mechanism of altered contractility in hearts from transgenic mice overexpressing the sarcoplasmic reticulum (SR) Ca²⁺ ATPase (SERCA2a). In particular, we sought to determine whether the reported increase in contractility is freqnency-dependent,...

Descripción completa

Detalles Bibliográficos
Autores principales: Hashimoto, Katsuji, Pérez, Néstor Gustavo, Kusuoka, Hideo, Baker, Debra L., Periasamy, Muthu, Marbán, Eduardo
Formato: Articulo
Lenguaje:Español
Publicado: 2000
Materias:
Medicina
Calcium
Ca-pump
contractile function
e-c coupling
SR
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/133702
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-133702
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Español
topic Medicina
Calcium
Ca-pump
contractile function
e-c coupling
SR
spellingShingle Medicina
Calcium
Ca-pump
contractile function
e-c coupling
SR
Hashimoto, Katsuji
Pérez, Néstor Gustavo
Kusuoka, Hideo
Baker, Debra L.
Periasamy, Muthu
Marbán, Eduardo
Frequency-dependent changes in calcium cycling and contractile activation in SERCA2a transgenic mice
topic_facet Medicina
Calcium
Ca-pump
contractile function
e-c coupling
SR
description Objective: This study was undertaken to investigate the mechanism of altered contractility in hearts from transgenic mice overexpressing the sarcoplasmic reticulum (SR) Ca²⁺ ATPase (SERCA2a). In particular, we sought to determine whether the reported increase in contractility is freqnency-dependent, as might be expected if attributable to changes in SR Ca²⁺ loading. Methods: Intracellular [Ca²⁺] and contractile force were measured at room temperature (22 °C) simultaneously in fura-2-loaded isometrically-contracting trabeculae dissected from the hearts of FVB/N control (n=6) or SERCA2a transgenic (n=6) mice. Results: SERCA transgenics exhibit a positive force-frequency relationship, but this was flat in age- and strain-matched controls. SERCA transgenics exhibit a sizable increase in calcium transient amplitude relative to controls, with a concomitant increase in force generation at higher frequencies of stimulation. Amplitudes of Ca²⁺ transients (transgenics: 1.56 ± 0.09 μmol/l, controls: 1.21 ± 0.14) and twitches (transgenics: 21.71 ± 0.91 mN/mm², controls: 13.74 ± 1.67) were significantly different at 2.0 Hz stimulation (P < 0.05). Conclusion: An increase in SERCA expression increases the ability of the sarcoplasmic reticulum to store calcium, such that more calcium is available to be released during each heartbeat at higher stimulation rates.
format Articulo
Articulo
author Hashimoto, Katsuji
Pérez, Néstor Gustavo
Kusuoka, Hideo
Baker, Debra L.
Periasamy, Muthu
Marbán, Eduardo
author_facet Hashimoto, Katsuji
Pérez, Néstor Gustavo
Kusuoka, Hideo
Baker, Debra L.
Periasamy, Muthu
Marbán, Eduardo
author_sort Hashimoto, Katsuji
title Frequency-dependent changes in calcium cycling and contractile activation in SERCA2a transgenic mice
title_short Frequency-dependent changes in calcium cycling and contractile activation in SERCA2a transgenic mice
title_full Frequency-dependent changes in calcium cycling and contractile activation in SERCA2a transgenic mice
title_fullStr Frequency-dependent changes in calcium cycling and contractile activation in SERCA2a transgenic mice
title_full_unstemmed Frequency-dependent changes in calcium cycling and contractile activation in SERCA2a transgenic mice
title_sort frequency-dependent changes in calcium cycling and contractile activation in serca2a transgenic mice
publishDate 2000
url http://sedici.unlp.edu.ar/handle/10915/133702
work_keys_str_mv AT hashimotokatsuji frequencydependentchangesincalciumcyclingandcontractileactivationinserca2atransgenicmice
AT pereznestorgustavo frequencydependentchangesincalciumcyclingandcontractileactivationinserca2atransgenicmice
AT kusuokahideo frequencydependentchangesincalciumcyclingandcontractileactivationinserca2atransgenicmice
AT bakerdebral frequencydependentchangesincalciumcyclingandcontractileactivationinserca2atransgenicmice
AT periasamymuthu frequencydependentchangesincalciumcyclingandcontractileactivationinserca2atransgenicmice
AT marbaneduardo frequencydependentchangesincalciumcyclingandcontractileactivationinserca2atransgenicmice
bdutipo_str Repositorios
_version_ 1764820455288471552

Ejemplares similares