Pacioretty, L. M., et al. “Restoration of the Transient Outward Potassium Current by Noradrenaline in Chagasic Canine Epicardium”. The Journal of Physiology, vol. 500 ( Pt 1), 1997, pp. 75-83, https://scholar2.islandarchives.ca/islandora/object/ir%3A3126.

Genre

  • Journal Article
Contributors
Author: Pacioretty, L. M.
Author: Barr, S. C.
Author: Han, W.
Author: Gilmour, R. F., J.
Date Issued
1997
Abstract

1. The transient outward potassium current (Ito) is reduced in canine epicardial myocytes during the acute stage of infection with Trypanosoma cruzi (Chagas' disease). Sympathetic nerve terminals are also destroyed during the acute stage of this disease. To test whether the reduction of Ito is related to the absence of sympathetic innervation, acutely infected isolated epicardial myocytes were exposed in vitro to the sympathetic neurotransmitter noradrenaline (NA) and the effects of NA exposure on Ito were determined. 2. Continuous exposure to NA (1.0 microM) for 0-6 h had no effect on Ito density, whereas exposure to NA for 24 h significantly increased Ito density. Ito was also restored 24 h after a 1 h exposure to NA. Cell capacitance was not significantly affected by NA. 3. The alpha1-adrenergic receptor antagonist prazosin (0.1 microM) blocked the effects of NA on Ito, but the beta-adrenergic receptor antagonist propranolol (20 microM) did not. The beta-adrenergic receptor agonist isoprenaline (1 microM) had no effect on Ito. 4. Restoration of Ito by NA was prevented by pretreatment with neomycin (100 microM), a phospholipase C inhibitor, but not by pretreatment with 100-400 ng ml(-1) pertussis toxin (PTX). 5. The protein kinase C (PKC) activator phorbol 12-myristate 13-acetate (0.1 microM) mimicked the effect of NA on Ito, whereas the inactive analogue 4alpha-phorbol (20 microM) had no effect on Ito. Pretreatment with bisindolylmaleimide (0.1 microM), a specific PKC inhibitor, completely blocked the effect of NA on Ito. 6. Thus, NA restores Ito in chagasic canine epicardial myocytes. The induction of Ito by NA appears to result from alpha1-adrenergic stimulation of PKC via a PTX-insensitive signalling cascade. These results suggest that the reduction of Ito in chagasic myocytes during the acute stage of Chagas' disease may reflect the lack of the trophic effects of sympathetic innervation.

Note

Department of Physiology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853-6401, USA.

ENGLAND

Cambridge Univ. Press : Oxford : Blackwell

Accession Number: 9097934. Language: English. Language Code: eng. Date Revised: 20091118. Date Created: 19970703. Date Completed: 19970703. Update Code: 20111122. Publication Type: In Vitro; Journal Article; Research Support, Non-U.S. Gov't. Journal ID: 0266262. Publication Model: Print. Cited Medium: Print. NLM ISO Abbr: J. Physiol. (Lond.) PubMed Central ID: PMC1159360. Cites: Circ Res. 1992 Sep;71(3):673-88. (PMID: 1323437). Cites: Biochem J. 1996 Feb 15;314 ( Pt 1):115-21. (PMID: 8660271). Cites: Clin Microbiol Rev. 1992 Oct;5(4):400-19. (PMID: 1423218). Cites: Circ Res. 1992 Apr;70(4):733-42. (PMID: 1551199). Cites: J Med Chem. 1992 Mar 20;35(6):994-1001. (PMID: 1552513). Cites: Am J Vet Res. 1992 Apr;53(4):521-7. (PMID: 1586022). Cites: Am J Vet Res. 1991 Dec;52(12):2033-9. (PMID: 1789518). Cites: J Physiol. 1990 Dec;431:689-712. (PMID: 1983124). Cites: Experientia. 1990 Jan 15;46(1):81-4. (PMID: 2153573). Cites: J Clin Invest. 1990 Apr;85(4):1206-14. (PMID: 2156896). Cites: Circ Res. 1988 Jan;62(1):116-26. (PMID: 2826039). Cites: J Mol Cell Cardiol. 1988 Dec;20(12):1081-5. (PMID: 2907916). Cites: Pflugers Arch. 1981 Apr;390(1):102-6. (PMID: 6264382). Cites: Pflugers Arch. 1981 Aug;391(2):85-100. (PMID: 6270629). Cites: Circ Res. 1994 Aug;75(2):296-303. (PMID: 7518363). Cites: J Biol Chem. 1995 Jul 21;270(29):17148-53. (PMID: 7615510). Cites: Biochem J. 1995 Jul 15;309 ( Pt 2):437-43. (PMID: 7626007). Cites: Mol Cell Biol. 1995 Sep;15(9):4930-8. (PMID: 7651411). Cites: J Neural Transm Gen Sect. 1994;97(2):149-59. (PMID: 7873124). Cites: J Biol Chem. 1995 Mar 10;270(10):5172-80. (PMID: 7890627). Cites: J Exp Med. 1994 Oct 1;180(4):1535-40. (PMID: 7931085). Cites: Circ Res. 1994 Dec;75(6):999-1005. (PMID: 7955154). Cites: Circulation. 1994 Sep;90(3):1350-6. (PMID: 8087945). Cites: J Biol Chem. 1994 Feb 4;269(5):3775-82. (PMID: 8106422). Cites: J Exp Med. 1994 Mar 1;179(3):1017-22. (PMID: 8113670). Cites: J Biol Chem. 1994 May 6;269(18):13490-6. (PMID: 8175782). Cites: Mol Pharmacol. 1993 Oct;44(4):784-95. (PMID: 8232229). Cites: Circ Res. 1993 Aug;73(2):386-94. (PMID: 8330381). Cites: Infect Immun. 1996 May;64(5):1770-7. (PMID: 8613390). Cites: Circulation. 1992 Mar;85(3):1175-88. (PMID: 1371431). Linking ISSN: 00223751. Subset: IM. Date of Electronic Publication: 19970401; ID: 9097934

Language

  • English

Subjects

  • Indoles/pharmacology
  • Mice, Inbred A
  • PERTUSSIS TOXIN
  • Isoproterenol/pharmacology
  • Virulence Factors, Bordetella/pharmacology
  • Pericardium/physiology
  • Heart/*physiopathology
  • Second Messenger Systems
  • Prazosin/pharmacology
  • Phorbols/pharmacology
  • Chagas Disease/*physiopathology
  • Heart/physiology
  • Reference Values
  • Potassium Channels/drug effects
  • Maleimides/pharmacology
  • Pericardium/*physiopathology
  • animals
  • Neomycin/pharmacology
  • Patch-Clamp Techniques
  • Dogs
  • Potassium Channels/*physiology
  • Mice
  • Trypanosoma cruzi
  • Membrane Potentials/drug effects
  • Norepinephrine/*pharmacology
  • Pericardium/innervation
  • Tetradecanoylphorbol Acetate/pharmacology
Page range
75-83
Host Title
The Journal of Physiology
Host Abbreviated Title
J Physiol
Volume
500 ( Pt 1)
ISSN
0022-3751

Department