Abstract
1. Angiotensin II receptor blockers (AIIRBs) have been shown to prevent atrial fibrillation. The pulmonary veins (PVs) are the most important focus for the generation of atrial fibrillation. The aim of this study was to evaluate whether angiotensin II or AIIRB may change the arrhythmogenic activity of the PVs. 2. Conventional microelectrodes and whole-cell patch clamps were used to investigate the action potentials (APs) and ionic currents in isolated rabbit PV tissue and single cardiomyocytes before and after administering angiotensin II or losartan (AIIRB). 3. In the tissue preparations, angiotensin II induced delayed after-depolarizations (1, 10, and 100 nM) and accelerated the automatic rhythm (10 and 100 nM). Angiotensin II (100 nM) prolonged the AP duration and increased the contractile force (10 and 100 nM). Losartan (1 and 10 μM) inhibited the automatic rhythm. Losartan (10 μM) prolonged the AP duration and reduced the contractile force (1 and 10 μM). 4. Angiotensin II reduced the transient outward potassium current (I to) but increased the L-type calcium, delayed rectifier potassium (I K), transient inward (I ti), pacemaker, and Na +-Ca 2+ exchanger (NCX) currents in the PV cardiomyocytes. Losartan decreased the I to, I K, I ti, and NCX currents. 5. In conclusion, angiotensin II and AIIRB modulate the PV electrical activity, which may play a role in the pathophysiology of atrial fibrillation.
| Original language | English |
|---|---|
| Pages (from-to) | 12-22 |
| Number of pages | 11 |
| Journal | British Journal of Pharmacology |
| Volume | 147 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Jan 2006 |
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Keywords
- Angiotensin II
- Atrial fibrillation
- Ionic currents
- Pulmonary vein
ASJC Scopus subject areas
- Pharmacology
Cite this
Angiotensin II and angiotensin II receptor blocker modulate the arrhythmogenic activity of pulmonary veins. / Chen, Yi Jen; Chen, Yao Chang; Tai, Ching Tai; Yeh, Hung I.; Lin, Cheng I.; Chen, Shih Ann.
In: British Journal of Pharmacology, Vol. 147, No. 1, 01.2006, p. 12-22.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Angiotensin II and angiotensin II receptor blocker modulate the arrhythmogenic activity of pulmonary veins
AU - Chen, Yi Jen
AU - Chen, Yao Chang
AU - Tai, Ching Tai
AU - Yeh, Hung I.
AU - Lin, Cheng I.
AU - Chen, Shih Ann
PY - 2006/1
Y1 - 2006/1
N2 - 1. Angiotensin II receptor blockers (AIIRBs) have been shown to prevent atrial fibrillation. The pulmonary veins (PVs) are the most important focus for the generation of atrial fibrillation. The aim of this study was to evaluate whether angiotensin II or AIIRB may change the arrhythmogenic activity of the PVs. 2. Conventional microelectrodes and whole-cell patch clamps were used to investigate the action potentials (APs) and ionic currents in isolated rabbit PV tissue and single cardiomyocytes before and after administering angiotensin II or losartan (AIIRB). 3. In the tissue preparations, angiotensin II induced delayed after-depolarizations (1, 10, and 100 nM) and accelerated the automatic rhythm (10 and 100 nM). Angiotensin II (100 nM) prolonged the AP duration and increased the contractile force (10 and 100 nM). Losartan (1 and 10 μM) inhibited the automatic rhythm. Losartan (10 μM) prolonged the AP duration and reduced the contractile force (1 and 10 μM). 4. Angiotensin II reduced the transient outward potassium current (I to) but increased the L-type calcium, delayed rectifier potassium (I K), transient inward (I ti), pacemaker, and Na +-Ca 2+ exchanger (NCX) currents in the PV cardiomyocytes. Losartan decreased the I to, I K, I ti, and NCX currents. 5. In conclusion, angiotensin II and AIIRB modulate the PV electrical activity, which may play a role in the pathophysiology of atrial fibrillation.
AB - 1. Angiotensin II receptor blockers (AIIRBs) have been shown to prevent atrial fibrillation. The pulmonary veins (PVs) are the most important focus for the generation of atrial fibrillation. The aim of this study was to evaluate whether angiotensin II or AIIRB may change the arrhythmogenic activity of the PVs. 2. Conventional microelectrodes and whole-cell patch clamps were used to investigate the action potentials (APs) and ionic currents in isolated rabbit PV tissue and single cardiomyocytes before and after administering angiotensin II or losartan (AIIRB). 3. In the tissue preparations, angiotensin II induced delayed after-depolarizations (1, 10, and 100 nM) and accelerated the automatic rhythm (10 and 100 nM). Angiotensin II (100 nM) prolonged the AP duration and increased the contractile force (10 and 100 nM). Losartan (1 and 10 μM) inhibited the automatic rhythm. Losartan (10 μM) prolonged the AP duration and reduced the contractile force (1 and 10 μM). 4. Angiotensin II reduced the transient outward potassium current (I to) but increased the L-type calcium, delayed rectifier potassium (I K), transient inward (I ti), pacemaker, and Na +-Ca 2+ exchanger (NCX) currents in the PV cardiomyocytes. Losartan decreased the I to, I K, I ti, and NCX currents. 5. In conclusion, angiotensin II and AIIRB modulate the PV electrical activity, which may play a role in the pathophysiology of atrial fibrillation.
KW - Angiotensin II
KW - Atrial fibrillation
KW - Ionic currents
KW - Pulmonary vein
UR - http://www.scopus.com/inward/record.url?scp=30344463005&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=30344463005&partnerID=8YFLogxK
U2 - 10.1038/sj.bjp.0706445
DO - 10.1038/sj.bjp.0706445
M3 - Article
C2 - 16273119
AN - SCOPUS:30344463005
VL - 147
SP - 12
EP - 22
JO - British Journal of Pharmacology
JF - British Journal of Pharmacology
SN - 0007-1188
IS - 1
ER -