Limits...
Ageing is associated with deterioration of calcium homeostasis in isolated human right atrial myocytes.

Herraiz-Martínez A, Álvarez-García J, Llach A, Molina CE, Fernandes J, Ferrero-Gregori A, Rodríguez C, Vallmitjana A, Benítez R, Padró JM, Martínez-González J, Cinca J, Hove-Madsen L - Cardiovasc. Res. (2015)

Bottom Line: Protein levels were determined by western blot.Ageing was associated with the following electrophysiological changes: (i) a 3.2-fold decrease in the calcium transient (P < 0.01); (ii) reduction of the L-type calcium current (ICa) amplitude (2.4 ± 0.3 pA/pF vs. 1.4 ± 0.2 pA/pF, P < 0.01); (iii) lower levels of L-type calcium channel alpha-subunit (P < 0.05); (iv) lower rates of both fast (14.5 ± 0.9 ms vs. 20.9 ± 1.9, P < 0.01) and slow (73 ± 3 vs. 120 ± 12 ms, P < 0.001) ICa inactivation; and (v) a decrease in the sarcoplasmic reticulum calcium content (10.1 ± 0.8 vs. 6.4 ± 0.6 amol/pF, P < 0.005) associated with a significant decrease in both SERCA2 (P < 0.05) and calsequestrin-2 (P < 0.05) protein levels.In contrast, ageing did not affect spontaneous sarcoplasmic reticulum calcium release.

View Article: PubMed Central - PubMed

Affiliation: Cardiovascular Research Centre CSIC-ICCC and IIB-Sant Pau, Hospital de la Santa Creu i Sant Pau, St Antoni Mª Claret 167, Barcelona 08025, Spain.

No MeSH data available.


Related in: MedlinePlus

Effects of ageing on intrinsic L-type calcium channel properties. (A) Representative ICa traces obtained after a prepulse to different membrane potentials (given above traces). Current traces are normalized to the ICa amplitude at −50 mV. (B) Relationship between the prepulse potential and the ICa amplitude. (C) Bar diagram of the voltage for half-maximal ICa inactivation. Values were obtained by fitting data in (B) with a Boltzmann equation. (D) Representative ICa traces elicited at different times (given above traces) after the preceding stimulation pulse. (E) Relationship between pulse interval and the recovery of the ICa amplitude. Values were normalized to the ICa amplitude at 0.6 s. (F) Bar diagram of the time for half-maximal recovery of ICa. Values were obtained by fitting data in (E) with an exponentially decaying function. (G) Normalized ICa traces from a young and an old patient. Average fast (tau-1) and slow (tau-2) time constants are shown in the right panel. P-values for significant differences are indicated for corresponding bars. All values are from 21 young (<55) and 17 old (≥75) patients (n.s. indicates a non-significant difference).
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4362404&req=5

CVV046F3: Effects of ageing on intrinsic L-type calcium channel properties. (A) Representative ICa traces obtained after a prepulse to different membrane potentials (given above traces). Current traces are normalized to the ICa amplitude at −50 mV. (B) Relationship between the prepulse potential and the ICa amplitude. (C) Bar diagram of the voltage for half-maximal ICa inactivation. Values were obtained by fitting data in (B) with a Boltzmann equation. (D) Representative ICa traces elicited at different times (given above traces) after the preceding stimulation pulse. (E) Relationship between pulse interval and the recovery of the ICa amplitude. Values were normalized to the ICa amplitude at 0.6 s. (F) Bar diagram of the time for half-maximal recovery of ICa. Values were obtained by fitting data in (E) with an exponentially decaying function. (G) Normalized ICa traces from a young and an old patient. Average fast (tau-1) and slow (tau-2) time constants are shown in the right panel. P-values for significant differences are indicated for corresponding bars. All values are from 21 young (<55) and 17 old (≥75) patients (n.s. indicates a non-significant difference).

Mentions: Analysis of intrinsic ICa properties in the older and younger patients showed no significant differences in voltage-dependent inactivation (Figure 3A–C) or in recovery of ICa from inactivation (Figure 3D–F). However, both fast and slow steady-state ICa-inactivation were significantly slower in patients 75 years or older when compared with patients younger than 55 years (Figure 3G). Thus, the time constant (tau-1) for fast ICa inactivation increased by 44% from 14.5 ± 0.9 ms in young to 20.9 ± 1.9 ms in old patients (P < 0.01). Similarly the tau-2 for slow ICa inactivation was 73 ± 3 ms in young vs. 120 ± 12 ms in old patients (P < 0.001).Figure 3


Ageing is associated with deterioration of calcium homeostasis in isolated human right atrial myocytes.

Herraiz-Martínez A, Álvarez-García J, Llach A, Molina CE, Fernandes J, Ferrero-Gregori A, Rodríguez C, Vallmitjana A, Benítez R, Padró JM, Martínez-González J, Cinca J, Hove-Madsen L - Cardiovasc. Res. (2015)

Effects of ageing on intrinsic L-type calcium channel properties. (A) Representative ICa traces obtained after a prepulse to different membrane potentials (given above traces). Current traces are normalized to the ICa amplitude at −50 mV. (B) Relationship between the prepulse potential and the ICa amplitude. (C) Bar diagram of the voltage for half-maximal ICa inactivation. Values were obtained by fitting data in (B) with a Boltzmann equation. (D) Representative ICa traces elicited at different times (given above traces) after the preceding stimulation pulse. (E) Relationship between pulse interval and the recovery of the ICa amplitude. Values were normalized to the ICa amplitude at 0.6 s. (F) Bar diagram of the time for half-maximal recovery of ICa. Values were obtained by fitting data in (E) with an exponentially decaying function. (G) Normalized ICa traces from a young and an old patient. Average fast (tau-1) and slow (tau-2) time constants are shown in the right panel. P-values for significant differences are indicated for corresponding bars. All values are from 21 young (<55) and 17 old (≥75) patients (n.s. indicates a non-significant difference).
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4362404&req=5

CVV046F3: Effects of ageing on intrinsic L-type calcium channel properties. (A) Representative ICa traces obtained after a prepulse to different membrane potentials (given above traces). Current traces are normalized to the ICa amplitude at −50 mV. (B) Relationship between the prepulse potential and the ICa amplitude. (C) Bar diagram of the voltage for half-maximal ICa inactivation. Values were obtained by fitting data in (B) with a Boltzmann equation. (D) Representative ICa traces elicited at different times (given above traces) after the preceding stimulation pulse. (E) Relationship between pulse interval and the recovery of the ICa amplitude. Values were normalized to the ICa amplitude at 0.6 s. (F) Bar diagram of the time for half-maximal recovery of ICa. Values were obtained by fitting data in (E) with an exponentially decaying function. (G) Normalized ICa traces from a young and an old patient. Average fast (tau-1) and slow (tau-2) time constants are shown in the right panel. P-values for significant differences are indicated for corresponding bars. All values are from 21 young (<55) and 17 old (≥75) patients (n.s. indicates a non-significant difference).
Mentions: Analysis of intrinsic ICa properties in the older and younger patients showed no significant differences in voltage-dependent inactivation (Figure 3A–C) or in recovery of ICa from inactivation (Figure 3D–F). However, both fast and slow steady-state ICa-inactivation were significantly slower in patients 75 years or older when compared with patients younger than 55 years (Figure 3G). Thus, the time constant (tau-1) for fast ICa inactivation increased by 44% from 14.5 ± 0.9 ms in young to 20.9 ± 1.9 ms in old patients (P < 0.01). Similarly the tau-2 for slow ICa inactivation was 73 ± 3 ms in young vs. 120 ± 12 ms in old patients (P < 0.001).Figure 3

Bottom Line: Protein levels were determined by western blot.Ageing was associated with the following electrophysiological changes: (i) a 3.2-fold decrease in the calcium transient (P < 0.01); (ii) reduction of the L-type calcium current (ICa) amplitude (2.4 ± 0.3 pA/pF vs. 1.4 ± 0.2 pA/pF, P < 0.01); (iii) lower levels of L-type calcium channel alpha-subunit (P < 0.05); (iv) lower rates of both fast (14.5 ± 0.9 ms vs. 20.9 ± 1.9, P < 0.01) and slow (73 ± 3 vs. 120 ± 12 ms, P < 0.001) ICa inactivation; and (v) a decrease in the sarcoplasmic reticulum calcium content (10.1 ± 0.8 vs. 6.4 ± 0.6 amol/pF, P < 0.005) associated with a significant decrease in both SERCA2 (P < 0.05) and calsequestrin-2 (P < 0.05) protein levels.In contrast, ageing did not affect spontaneous sarcoplasmic reticulum calcium release.

View Article: PubMed Central - PubMed

Affiliation: Cardiovascular Research Centre CSIC-ICCC and IIB-Sant Pau, Hospital de la Santa Creu i Sant Pau, St Antoni Mª Claret 167, Barcelona 08025, Spain.

No MeSH data available.


Related in: MedlinePlus