title: Acetylcholine Attenuates Hydrogen Peroxide-Induced Intracellular Calcium Dyshomeostasis Through Both Muscarinic and Nicotinic Receptors in Cardiomyocytes.
abstract: OBJECTIVE
  Oxidative stress induced intracellular Ca2+ overload plays an important role in the pathophysiology of several heart diseases. Acetylcholine (ACh) has been shown to suppress reactive oxygen species generation during oxidative stress. However, there is little information regarding the effects of ACh on the intracellular Ca2+ regulation in the presence of oxidative stress. Therefore, we investigated the effects of ACh applied before or after hydrogen peroxide (H2O2) treatment on the intracellular Ca2+ regulation in isolated cardiomyocytes.
  
  
  METHODS
  Single ventricular myocytes were isolated from the male Wistar rats for the intracellular Ca2+ transient study by a fluorimetric ratio technique.
  
  
  RESULTS
  H2O2 significantly decreased both of intracellular Ca2+ transient amplitude and decay rate. ACh applied before, but not after, H2O2 treatment attenuated the reduction of intracellular Ca2+ transient amplitude and decay rate. Both atropine (a muscarinic acetylcholine receptor blocker) and mecamylamine (a nicotinic acetylcholine receptor blocker) significantly decreased the protective effects of acetylcholine on the intracellular Ca2+ regulation. Moreover, the combination of atropine and mecamylamine completely abolished the protective effects of acetylcholine on intracellular Ca2+ transient amplitude and decay rate.
  
  
  CONCLUSIONS
  ACh pretreatment attenuates H2O2-induced intracellular Ca2+ dyshomeostasis through both muscarinic and nicotinic receptors.
authors.affiliation: School of Medicine, Mae Fah Luang University, Chiang Rai, Thailand.
authors.forename: Siripong
authors.initials: S
authors.lastname: Palee
authors.forename: Nattayaporn
authors.initials: N
authors.lastname: Apaijai
authors.forename: Krekwit
authors.initials: K
authors.lastname: Shinlapawittayatorn
authors.forename: Siriporn C
authors.initials: SC
authors.lastname: Chattipakorn
authors.forename: Nipon
authors.initials: N
authors.lastname: Chattipakorn
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D006706:Homeostasis / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008464:Mecamylamine / Q000494:pharmacology; D018727:Muscarinic Antagonists / Q000494:pharmacology; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000378:metabolism; D018733:Nicotinic Antagonists / Q000494:pharmacology; D016877:Oxidants / Q000494:pharmacology; D017208:Rats, Wistar; D011976:Receptors, Muscarinic / Q000378:metabolism*; D011978:Receptors, Nicotinic / Q000378:metabolism*; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D018727:Muscarinic Antagonists; D018733:Nicotinic Antagonists; D016877:Oxidants; D011976:Receptors, Muscarinic; D011978:Receptors, Nicotinic; D014665:Vasodilator Agents; D008464:Mecamylamine; D001285:Atropine; D006861:Hydrogen Peroxide; D000109:Acetylcholine; D002118:Calcium