George J. Schwartz, M.D.

George J. Schwartz, M.D.

Contact Information

University of Rochester Medical Center
School of Medicine and Dentistry
601 Elmwood Ave, Box 777
Rochester, NY 14642

Office: (585) 275-9784
Fax: (585) 756-8054

Research Bio

Dr. Schwartz' research interests are:
1) Molecular physiology of acid-base disturbances
2) Kidney tubular acidosis
3) Disorders of sodium, potassium, and magnesium transport
4) Carbonic anhydrase deficiency diseases
5) Assessment of kidney function (glomerular filtration rate)



The long term goal is to determine how intercalated cells of the kidney cortical collecting duct (CCD) sense a change in extracellular pH and adapt by reversing their polarity of H+/HCO3 transporters. After exposure to a 3 h incubation at pH 6.8, rabbit CCDs, which normally secrete HCO3, reverse polarity, secrete H+ and endocytically remove apical Cl/HCO3 exchangers to stop HCO3 secretion. The novel protein hensin is expressed in the extracellular matrix (ECM) surrounding adapting HCO3-secreting intercalated cells (B-ICs) and plays a key role in this adaptation.

Aim 1 determines the mechanisms by which polymerized hensin is deposited in the ECM and how hensin signals the adaptation of B-ICs during metabolic acidosis. Other proteins interacting with hensin include integrins, galectin 3, and cyclophilin A (cyp A); these proteins may be regulated by acid-base disturbances and hensin polymerization. Cyclosporin (CsA) causes renal tubular acidosis and inhibits cyp A peptidyl prolyl isomerase activity. To assess CsA's effect, cultured intercalated cells are plated at high density in the presence of CsA and examined for hensin polymerization in the media and ECM. A cyp A "knockdown" model using siRNAs will be examined similarly; to determine if hensin fails to polymerize without this isomerase activity.

Aim 2 examines the adaptation of CCD ICs to metabolic alkalosis regarding proteins of the hensin pathway and investigates if in vitro alkalosis can reverse the adaptation occurring in response to in vivo metabolic acidosis.

Aim 3 addresses early events in response to metabolic acidosis. Our data suggest that low cell pH is the signal to initiate the adaptation; the role of the adjacent principal cell in this signaling will be determined. We will show whether low pH stimulates endothelin-1 and nitric oxide, and whether they mediate changes in HCO3 transport during acidosis. The early steps of tyrosine phosphorylation and c-Src activation in response to low pH will also be examined.

These studies will illustrate how ICs respond to acid-base perturbations and change functional polarity.

Awards & Honors (Local)

Ruth A. Lawrence Academic Faculty Service Award in Training | Golisano Children's Hospital 2012 - 2013
Listed in: Guide to America's Top Pediatricians 2006
Fellow of the American Society of Nephrology 2004 - Present
Fellow of the American Heart Association (Inaugural fellow of the Council on the Kidney in Cardiovascular Disease) 2003 - Present
Best Doctors, Inc. 2002 - Present
Specialist in Clinical Hypertension | American Society of Hypertension 1999 - Present
AMA Physician's Recognition Award 1977 - 1980
Magna Cum Laude | Colgate University 1968
Dana Scholar | Colgate University 1968
Phi Beta Kappa | Colgate University 1968
High Honors in Major (Chemistry) | Colgate University 1968
Honorary Journalism Society | Colgate University 1966 - 1968
Honorary Mathematics Society (KME) | Colgate University 1966 - 1968

Recent Journal Articles

Showing the 5 most recent journal articles. 137 available »

2016 May
Shafi T, Michels WM, Levey AS, Inker LA, Dekker FW, Krediet RT, Hoekstra T, Schwartz GJ, Eckfeldt JH, Coresh J. "Estimating residual kidney function in dialysis patients without urine collection." Kidney international. 2016 May; 89(5):1099-110. Epub 2016 Jan 21.
2016 Feb 20
Lucas GM, Atta MG, Zook K, McFall AM, Mehta SH, Fine DM, Stein JH, Schwartz GJ. "Factors associated with iohexol-based glomerular filtration rate slope over 36 months in HIV-negative and HIV-positive individuals." AIDS. 2016 Feb 20; 30(4):619-26.
2015 Oct
Shafi T, Levey AS, Inker LA, Schwartz GJ, Knight C, Abraham AG, Eckfeldt JH, Coresh J. "Plasma Iohexol Clearance for Assessing Residual Kidney Function in Dialysis Patients." American journal of kidney diseases : the official journal of the National Kidney Foundation. 2015 Oct; 66(4):728-30. Epub 2015 Jul 21.
2015 Sep 1
Purkerson JM, Schwaderer AL, Nakamori A, Schwartz GJ. "Distinct ?-intercalated cell morphology and its modification by acidosis define regions of the collecting duct." American journal of physiology. Renal physiology. 2015 Sep 1; 309(5):F464-73. Epub 2015 Jun 17.
2015 Jul
Trachtman H, Frymoyer A, Lewandowski A, Greenbaum LA, Feig DI, Gipson DS, Warady BA, Goebel JW, Schwartz GJ, Lewis K, Anand R, Patel UD, . "Pharmacokinetics, Pharmacodynamics, and Safety of Lisinopril in Pediatric Kidney Transplant Patients: Implications for Starting Dose Selection." Clinical pharmacology and therapeutics. 2015 Jul; 98(1):25-33. Epub 2015 May 02.

Current Appointments

Professor - Department of Pediatrics, Pediatric Nephrology (SMD) - Primary

Specialties

Pediatric Nephrology - American Board of Pediatrics
Pediatrics - American Board of Pediatrics

Education

MD | Medicine | Case Western Reserve University School of Medicine1972
AB | Chemistry | Colgate University1968

Post-Doctoral Training & Residency

Fellowship in Pediatric Nephrology at Albert Einstein Medical Center07/01/1974 - 06/30/1976
Residency in Pediatrics at Children's Hospital of Philadelphia07/01/1973 - 06/30/1974
Internship in Pediatrics at Children's Hospital of Philadelphia07/01/1972 - 06/30/1973