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Aberrant sinus node firing during β-adrenergic stimulation leads to cardiac arrhythmias in diabetic mice. / Lubberding, Anniek F; Pereira, Laetitia; Xue, Jianbin et al.
In: Acta Physiologica (Print), Vol. 229, No. 1, e13444, 05.2020.Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review
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TY - JOUR
T1 - Aberrant sinus node firing during β-adrenergic stimulation leads to cardiac arrhythmias in diabetic mice
AU - Lubberding, Anniek F
AU - Pereira, Laetitia
AU - Xue, Jianbin
AU - Gottlieb, Lisa A
AU - Matchkov, Vladimir V
AU - Gomez, Ana M
AU - Thomsen, Morten B
N1 - © 2020 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.
PY - 2020/5
Y1 - 2020/5
N2 - AIM: Cardiovascular complications, including cardiac arrhythmias, result in high morbidity and mortality in patients with type-2 diabetes mellitus (T2DM). Clinical and experimental data suggest electrophysiological impairment of the natural pacemaker of the diabetic heart. The present study examined sinoatrial node (SAN) arrhythmias in a mouse model of T2DM and physiologically probed their underlying cause.METHODS: Electrocardiograms were obtained from conscious diabetic db/db and lean control db/+ mice. In vivo SAN function was probed through pharmacological autonomic modulation with isoprenaline, atropine and carbachol. Blood pressure stability and heart rate variability (HRV) were evaluated. Intrinsic SAN function was evaluated through ex vivo imaging of spontaneous Ca2+ transients in isolated SAN preparations.RESULTS: While lean control mice showed constant RR intervals during isoprenaline challenge, the diabetic mice experienced SAN arrhythmias with large RR fluctuations in a dose-dependent manner. These arrhythmias were completely abolished by atropine pre-treatment, while carbachol pretreatment significantly increased SAN arrhythmia frequency in the diabetic mice. Blood pressure and HRV were comparable in db/db and db/+ mice, suggesting that neither augmented baroreceptor feedback nor autonomic neuropathy is a likely arrhythmia mechanism. Cycle length response to isoprenaline was comparable in isolated SAN preparations from db/db and db/+ mice; however, Ca2+ spark frequency was significantly increased in db/db mice compared to db/+ at baseline and after isoprenaline.CONCLUSION: Our results demonstrate a dysfunction of cardiac pacemaking in an animal model of T2DM upon challenge with a β-adrenergic agonist. Ex vivo, higher Ca2+ spark frequency is present in diabetic mice, which may be directly linked to in vivo arrhythmias.
AB - AIM: Cardiovascular complications, including cardiac arrhythmias, result in high morbidity and mortality in patients with type-2 diabetes mellitus (T2DM). Clinical and experimental data suggest electrophysiological impairment of the natural pacemaker of the diabetic heart. The present study examined sinoatrial node (SAN) arrhythmias in a mouse model of T2DM and physiologically probed their underlying cause.METHODS: Electrocardiograms were obtained from conscious diabetic db/db and lean control db/+ mice. In vivo SAN function was probed through pharmacological autonomic modulation with isoprenaline, atropine and carbachol. Blood pressure stability and heart rate variability (HRV) were evaluated. Intrinsic SAN function was evaluated through ex vivo imaging of spontaneous Ca2+ transients in isolated SAN preparations.RESULTS: While lean control mice showed constant RR intervals during isoprenaline challenge, the diabetic mice experienced SAN arrhythmias with large RR fluctuations in a dose-dependent manner. These arrhythmias were completely abolished by atropine pre-treatment, while carbachol pretreatment significantly increased SAN arrhythmia frequency in the diabetic mice. Blood pressure and HRV were comparable in db/db and db/+ mice, suggesting that neither augmented baroreceptor feedback nor autonomic neuropathy is a likely arrhythmia mechanism. Cycle length response to isoprenaline was comparable in isolated SAN preparations from db/db and db/+ mice; however, Ca2+ spark frequency was significantly increased in db/db mice compared to db/+ at baseline and after isoprenaline.CONCLUSION: Our results demonstrate a dysfunction of cardiac pacemaking in an animal model of T2DM upon challenge with a β-adrenergic agonist. Ex vivo, higher Ca2+ spark frequency is present in diabetic mice, which may be directly linked to in vivo arrhythmias.
U2 - 10.1111/apha.13444
DO - 10.1111/apha.13444
M3 - Journal article
C2 - 31953990
VL - 229
JO - Acta Physiologica (Print)
JF - Acta Physiologica (Print)
SN - 1748-1708
IS - 1
M1 - e13444
ER -