Dr. Clive Baumgarten
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Contact Information
Department of Physiology and Biophysics Virginia Commonwealth University P.O. Box 980551 Richmond, Virginia 23298-0551 Tel: 804-828-4773 Fax: 804-828-7382 email: baumgart@vcu.edu |
Clive M. Baumgarten received his undergraduate degree in Biology in 1970 and his Ph.D. in Pharmacology in 1976 from Northwestern University. After completing postdoctoral training in the laboratory of Dr. H.A. Fozzard at the University of Chicago, Dr. Baumgarten joined the faculty in 1979.
Research
Research in my laboratory is directed towards understanding the electrical activity of the heart at the cell, membrane, and channel level. Patch-clamp techniques are used to voltage clamp isolated cardiac myocytes (whole-cell and perforated-patch) and to study the activity of single ion channels in on-cell and excised patches. Recent studies have focused on the regulation of mechanosensitive (stretch-activated) and volume-sensitive (swelling-activated) ion channels in normal cells and cells isolated from hearts in congestive failure. We discovered that both cation and anion volume/stretch-activated channels are persistently activated in congestive failure. These channels affect both the electrical activity of the heart and myocyte volume. We found that the anion volume-activated channel (ICl,swell) is regulated by protein kinase C and protein phosphatases (PP2a and calcineurin).
Recently, we discovered that stretch- and swelling-induced activation of ICl,swell also is regulated by a signaling cascade involving angiotensin II AT1 receptors, EGFR kinase, PI-3K, and NAD(P)H oxidase, and ultimately reactive oxygen species (ROS) including superoxide anion (·O2-) and H2O2. The angiotensin II – ROS cascade is intimately involved in the signaling that leads to cardiac hypertrophy and dilated cardiomyopathy. In addition, we developed digital video microscopy methods for identifying the effect of ion transport on cardiac cell volume. This methodology lead to the discovery of the role of cGMP and Na/K/2Cl cotransport in cardiac cell volume regulation and presently is used to study the effects of stretch- and volume-sensitive channels on cell volume.
The laboratory also has studied the regulation of Na channels by triiodo-L-tyronine, local anesthetics, carboxyl reagents, and gadolinium. Our work focuses on fundamental phenomena in cell physiology and membrane biophysics of cardiac cells. This combines the excitement of cutting-edge basic science with the hope that we will contribute to alleviating heart disease, the leading cause of death among both men and women.
Teaching
I teach cardiovascular physiology in both the MI and MII medical courses and in our graduate Mammalian Physiology course (PHIS501). I also developed and direct Ion Channels in Membranes (PHIS620) and teach in Advanced Cardiovascular Physiology (PHIS612). Previously I have participated in graduate courses on Cell Physiology, Cell and Molecular Neurophysiology, and Physical Principles in Physiological Systems.
Selected Publications
Ren Z, Raucci FJ Jr, Browe DM, Baumgarten CM. Regulation of swelling-activated Cl current by angiotensin II signalling and NADPH oxidase in rabbit ventricle. Cardiovasc. Res. 77, 73-80, 2008. PubMed
Browe DM, Baumgarten CM. EGFR kinase regulates volume-sensitive chloride current elicited by integrin stretch via PI-3K and NADPH oxidase in ventricular myocytes. J. Gen. Physiol.127:237-251, 2006. PubMed
Ren Z, Baumgarten CM. Antagonistic regulation of swelling-activated chloride current in rabbit ventricle by Src and EGFR protein tyrosine kinases. Am. J. Physiol. Heart Circ. Physiol. 288:H2628-2636, 2005. PubMed
Baumgarten CM. Cell volume-sensitive ion channels and transporters in cardiac myocytes. In: Cardiac Mechano-Electrical Feedback and Arrhythmias: From Pipette to Patient. Kohl P, Franz M, Sachs F, Eds. Saunders, Philadelphia, 2005, pp. 21-32. PDF Version
Browe DM, Baumgarten CM. Angiotensin (AT1) receptors and sarcolemmal NAD(P)H oxidase regulate a ß1 integrin stretch-induced Cl- current in rabbit ventricular myocytes. J. Gen. Physiol.124:273-287, 2004. PubMed
Browe DM, Baumgarten CM. Stretch of ß1 integrin activates an outwardly-rectifying chloride current via FAK and Src in rabbit ventricular myocytes. J. Gen. Physiol. 122:689-702, 2003. PubMed