NOVÁKOVÁ, Marie, Markéta BÉBAROVÁ, Bohuslava TARABOVÁ, Michal PÁSEK, Peter MATEJOVIČ and Ĺubica LACINOVÁ. Effects of sigma receptor ligand haloperidol on ionic currents in rat cardiomyocyte. Journal of Molecular and Cellular Cardiology. Amsterdam: Elsevier Ltd., 2006, vol. 40, No 6, p. 981. ISSN 0022-2828.
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Basic information
Original name Effects of sigma receptor ligand haloperidol on ionic currents in rat cardiomyocyte
Name in Czech Účinky ligandu sigma receptorů haloperidolu na iontové proudy u kardiomyocytu potkana
Authors NOVÁKOVÁ, Marie, Markéta BÉBAROVÁ, Bohuslava TARABOVÁ, Michal PÁSEK, Peter MATEJOVIČ and Ĺubica LACINOVÁ.
Edition Journal of Molecular and Cellular Cardiology, Amsterdam, Elsevier Ltd. 2006, 0022-2828.
Other information
Original language English
Type of outcome Article in a journal
Field of Study 30105 Physiology
Country of publisher Netherlands
Confidentiality degree is not subject to a state or trade secret
Impact factor Impact factor: 4.859
Organization unit Faculty of Medicine
UT WoS 000238304500321
Keywords in English sigma receptor;haloperidol;ionic currents;cardiomyocyte
Tags Cardiomyocyte, haloperidol, ionic currents, sigma receptor
Changed by Changed by: prof. MUDr. Marie Nováková, Ph.D., učo 1188. Changed: 21/11/2006 17:07.
Abstract
Sigma receptor ligand haloperidol is a neuroleptic drug with adverse cardiovascular effects, mainly ventricular arrhythmias. Its effects on the time course of action potential and on the basic ionic currents (sodium current INa, calcium current ICa, and potassium currents Ito,, IK1 and IK,end - current at the end of 250 ms pulse) were studied on enzymatically isolated rat ventricular cardiomyocytes using the whole cell patch clamp technique at room temperature. Haloperidol induced reversible and concentration-dependent inhibition of all investigated membrane currents. 1 ľmol/l inhibited INa by 39 %, ICa by 19.5 %, Ito by 23 % and IK,end by 14%, 10 ľmol/l haloperidol - by 95 %, 22 % 80 % 37 %, respectively, and IK1 by 29 %. Reversible loss of action potential in haloperidol was observed. Inhibition of Ito-amplitude by the drug was accompanied by acceleration of apparent inactivation. Both were voltage-independent. The time course of Ito recovery from inactivation was decelerated in the drug and 9 % of Ito-channels recovered with slow time constant about 1.4 s. It corresponded with a cummulation of inhibition at higher stimulation frequencies (3.3 Hz). We conclude that haloperidol inhibited all the main ionic current in rat cardiomyocytes with profound inhibition of INa that corresponded with loss of action potential. Inhibition of Ito is very likely caused by interaction of haloperidol with Ito-channels in open and in inactivated states as supported by the results of mathematical simulations.
Abstract (in Czech)
Ligand sigma receptorů haloperidol je neuroleptikum se závažnými vedlejšími kardiovaskulárními účinky, především ventrikulárními arytmiemi. Studovali jsme jeho účinky na průběh akčního potenciálu a na základní iontové proudy (sodíkový - INa, vápníkový - ICa a draslíkové proudy - Ito,, IK1 a IK,end - proud na konci 250 ms pulzu) u izolovaných komorových kardiomyocytů potkana, za použití whole cell patch clamp techniky, při pokojové teplotě. Haloperidol způsobil reverzibilní a koncentračně-závislou inhibici všech zkoumaných proudů. 1 umol/l inhiboval INa na 39 %, ICa na 19.5 %, Ito na 23 % a IK,end na 14%, 10 umol/l haloperidol - na 95 %, 22 % 80 % 37 %, a IK1 na 29 %. Byla také pozorována reverzibilní blokáda akčního napětí. Inhibice Ito-amplitudy byla doprovázena akcelerací zřejmé inaktivace, obojí napěťově závisle. Můžeme shrnout, že haloperidol inhibuje všechny hlavní iontové proudy v kardiomyocytu potkana, obzvláště markantně sodíkový proud což koresponduje s velkým efektem na akční napětí. Inhibice Ito je pravděpodobně způsobena interakcí haloperidolu s Ito-kanály v otevřeném a inaktivovaném stavu, což je podpořeno výsledky z matematických simulací.
Links
GA305/04/1385, research and development projectName: Modulační úloha sigma signalizace na elektromechanické vztahy izolovaného kardiomyocytu a srdce
Investor: Czech Science Foundation, Modulatory role of sigma signalling in electromechanical coupling of isolated cardiomyocyte and heart
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
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