D 2008

Acute effects of sigma receptor ligand haloperidol in rat and guinea pig isolated hearts

NOGOVÁ, Kateřina and Marie NOVÁKOVÁ

Basic information

Original name

Acute effects of sigma receptor ligand haloperidol in rat and guinea pig isolated hearts

Name in Czech

Akutní účinky ligandu sigma receptorů haloperidolu u izolovaných srdcí potkana a morčete

Edition

8. vyd. Kraków, Polsko, New Frontiers in Cardiovascular Research, p. 82-83, 1 pp. 2008

Publisher

Polish Academy of Arts

Other information

Language

English

Type of outcome

Stať ve sborníku

Field of Study

30105 Physiology

Country of publisher

Poland

Confidentiality degree

není předmětem státního či obchodního tajemství

Organization unit

Faculty of Medicine

Keywords in English

isolated heart;rat;guinea pig;sigma receptor;haloperidol;arrhythmias

Tags

International impact, Reviewed
Změněno: 28/1/2009 11:21, prof. MUDr. Marie Nováková, Ph.D.

Abstract

V originále

Sigma receptor ligands, mostly antipsychotics, can as an unwanted effect trigger episodes of cardiac arrhythmias - ventricular tachycardia, ventricular fibrillation, torsade de pointes, which occasionally culminate in sudden death. Mechanisms of these life-threatening side effects are not fully understood. Therefore we explored the role of typical sigma ligand haloperidol in susceptibility to develop arrhythmias on 3-D electrogram. Eleven adult male rats and eleven adult male guinea pigs were sacrificed under deep ether anesthesia. The hearts were perfused according to Langendorff with Krebs-Henseleit solution at constant pressure (85mmHg) and 37C (CaCl2, 1.2 mM). The experiment consists of four 30min periods: control, 10nM haloperidol, washout, 10nM haloperidol. Ten successive RR intervals were averaged at the end of control (steady state). This value was used for normalization of heart rate during the rest of experiment. Similarly, QT intervals were examined to determine L-QT. The incidence of arrhythmias was assessed according to Lambeth Conventions. Heart rate and QT interval showed similar changes in both models. Normalized heart rate declines in haloperidol applications and restores in washout. Almost all hearts exhibit L-QT. In guinea pig hearts, typical life-threatening arrhythmias occur; rat hearts show only premature ventricular beats in both haloperidol periods. This effect was attenuated in the next haloperidol phase. In conclusion, lengthened QT observed in our experimental models can explain the occurrence of arrhythmias. Unchanged QT interval in guinea pig hearts in the second haloperidol period can be reasoned by down-regulation of cardiac sigma receptors.

In Czech

Sigma receptor ligands, mostly antipsychotics, can as an unwanted effect trigger episodes of cardiac arrhythmias - ventricular tachycardia, ventricular fibrillation, torsade de pointes, which occasionally culminate in sudden death. Mechanisms of these life-threatening side effects are not fully understood. Therefore we explored the role of typical sigma ligand haloperidol in susceptibility to develop arrhythmias on 3-D electrogram. Eleven adult male rats and eleven adult male guinea pigs were sacrificed under deep ether anesthesia. The hearts were perfused according to Langendorff with Krebs-Henseleit solution at constant pressure (85mmHg) and 37C (CaCl2, 1.2 mM). The experiment consists of four 30min periods: control, 10nM haloperidol, washout, 10nM haloperidol. Ten successive RR intervals were averaged at the end of control (steady state). This value was used for normalization of heart rate during the rest of experiment. Similarly, QT intervals were examined to determine L-QT. The incidence of arrhythmias was assessed according to Lambeth Conventions. Heart rate and QT interval showed similar changes in both models. Normalized heart rate declines in haloperidol applications and restores in washout. Almost all hearts exhibit L-QT. In guinea pig hearts, typical life-threatening arrhythmias occur; rat hearts show only premature ventricular beats in both haloperidol periods. This effect was attenuated in the next haloperidol phase. In conclusion, lengthened QT observed in our experimental models can explain the occurrence of arrhythmias. Unchanged QT interval in guinea pig hearts in the second haloperidol period can be reasoned by down-regulation of cardiac sigma receptors.

Links

GA102/07/1473, research and development project
Name: Optické metody registrace elektrických potenciálů a koncentrace vápníku v srdci s laserovou stabilizací
Investor: Czech Science Foundation
MSM0021622402, plan (intention)
Name: Časná diagnostika a léčba kardiovaskulárních chorob
Investor: Ministry of Education, Youth and Sports of the CR, Early diagnostics and treatment of cardiovascular diseases