Areas of Investigation
I have established a broad based research program aimed at identifying the functional roles of ion channels in various regions of the heart and pharmacological modification of these ion channels.
Efficient ejection of blood from the heart requires coordinated contraction of the ventricles. The Purkinje fiber conduction system allows the rapid spread of electrical activity (via action potentials) throughout the ventricles and, therefore, activates the ventricular muscle in a uniform manner. Action potentials (AP) are an important physiological parameter: a) the upstroke of the AP is important for activation, b) APs modulate the refractory period, c) associated with each AP is a contraction (a process called excitation-contraction coupling or EC coupling).
The majority of my research can be subdivided these main areas. A summary of these projects are as follows:
1) Repolarization of the cardiac action potential is due to activation of several time- and voltage dependent ion channels which are selective only to K+ ions. These ion channels are located in the membrane of cardiac cells. Alterations in repolarization of the cardiac action potential play a critical role in the development of arrhythmias. In adult mammalian heart, the Purkinje fiber action potential waveform is different than the ventricular action potential. These differences in repolarization suggest different K+ currents and molecular proteins between the cell types. Among the repolarizing currents, (i) the inward rectifier K+ channel (ii) the transient outward current K+ channel; (iii) and the delayed rectifier(s) K+ channel are likely to be different. In addition, these K+ channels are frequently targeted by anti-arrhythmic drugs. Surprisingly, despite their extensive use in cardiac electrophysiology as well as their use as bioassays for pharmaceutical companies, very little is known about ionic complement of repolarizing K+ currents as well as the molecular identity of the K+ currents in Purkinje fibers compared to ventricular tissue. These studies should provide a better understanding of how Purkinje and ventricular tissue respond to certain pharmacological agents.
2) Excitation-contraction (EC) coupling. It is well established that intracellular calcium cycling is essential for normal EC coupling in cardiac cells. Recently, we have discovered regional differences in the mechanical aspects of EC coupling which are in part due to differences in intracellular calcium regulation. Using simultaneous voltage clamp and confocal imaging of calcium transients, we have sought to determine the mechanisms involved. It is essential to have a clear understanding of the mechanisms responsible for regional variations of contractile function in the normal heart before we can understand the basis for contractile dysfunction under various conditions such as hypertrophy or heart failure. For example during heart failure, there are defects in the Ca2+ transient and a depression of cardiac contraction; however, it is unclear if these defects are a result of alterations in Ca2+ regulatory proteins, a loss of surface ion channels, or loss of cardiac ultrstructure (T-tubules).
Research Scientist, Masonic Medical Research Institute
Email : , Phone : 315-624-7480
The laboratory of Dr. Jonathan Cordeiro focuses on the pre- and postnatal formation of the heart, including how different components of the heart develop and are assembled into a functional organ—in order to understand the basis of congenital and inherited heart disease.
Before joining the MMRI, Dr. Cordeiro worked at The Cardiovascular Research and Training Institute at the University of Utah in Salt Lake City (Drs. Kenneth Spitzer & John Bridge). Prior to that, he was a post-doctoral fellow in the Department of Physiology and Biophysics at the University of Calgary Under Dr. Wayne Giles). Training Originally from Canada, Dr. Cordeiro earned a B.Sc. in Pharmacology & Toxicology from the University of Western Ontario and a Ph.D. in Pharmacology at Dalhousie University in Halifax, Nova Scotia.
- Research Scientist, Masonic Medical Research Laboratory, Utica, NY, 2001-present
- Adjunct Professor, Department of Biology, Utica College, Utica, NY, 2014-present
- American Physiological Society, Cardiovascular Section
- American Physiological Society, Cell Section
- Biophysical Society
- Upstate New York Cardiac Electrophysiology Society
- 1990 - B.Sc.(Hons) - Pharmacology & Toxicology, University of Western Ontario
- 1995 – Ph.D. – Pharmacology, Dalhousie University
Honors and Awards
- 1985 Admission Scholarship, University of Western Ontario.
- 1985 Dean's Honour List, University of Western Ontario.
- 1989-1990 Dalhousie Graduate Fellowship, Dalhousie University.
- 1991 International Society for Heart Research Student Travel Award.
- 1991-1995 Research Traineeship, Heart and Stroke Foundation of Canada
- 1994 Pharmacology Society of Canada Student Travel Bursary.
- 1994 American Society for Pharmacology and Experimental Therapeutics Travel Award.
- 1995-1997 Research Post-Doctoral Fellowship, Heart and Stroke Foundation of Canada.
- 1995 Heart and Stroke Foundation of Canada/Canadian Cardiovascular Society Pharmaceutical Roundtable Fellow (sponsored by Bristol-Myers-Squibb Canada).
- 1996-1999 Post-Doctoral Fellowship, Alberta Heritage Foundation for Medical Research.
- 2001 American Heart Association Trainee Abstract Award.
- 2007 Masonic Medical Research Laboratory Employee of the Year
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