Introduction

The Division of Vascular Surgery has an active basic science research laboratory under the direction of J. Gregory Modrall, M.D.  Dr. Modrall and his colleagues are dedicated to understanding the molecular pathophysiology of renovascular hypertension (RVH) and, specificaly, regulation of the intrarenal renin-angiotensin-aldosterone system (RAAS) in the non-ischemic kidney during renovascular hypertension. An additional line of research in the laboratory relates to angiotensin processing in the kidney and its relationship to angiotensin II-induced renal injury.

Modrall Laboratory

Background

Renovascular hypertension affects an unknown percentage of patients with hypertension. At present there is no diagnostic test that is well suited to widespread screening of hypertensive patients for correctable renovascular disease. Understanding the molecular pathogenesis of the disease will facilitate the development of new, effective screening strategies and the identification of patients most likely to benefit from revascularization.

Projects

• Renovascular Hypertension / Regulaton of Intrarenal Ang II / Ang II-Induced Renal Injury   

  The research seeks to understand how hypertension is maintained in renovascular hypertension. Activation of the renin-angiotensin system has long been implicated in the pathogenesis renovascular hypertension. We are presently investigating the mechanism by which these local renin-angiotension systems are actived and regulated in renovascular hypertension. We are currently investigating three questions related to this topic: 1) The role of AT1 receptor-mediated uptake of circulating angiotensin II by the kidney; 2) The mechanisms by which intracrine production of angiotensin II is activated in proximal tubules of the kidney; 3) The role of differential sources and processing of angiotensin II in angiotensin II-induced renal injury. We employ a variety of animal models, including knockout mouse strategies. State of the arty physiology, cell biology and molecular biology techniques are employed. 

Personnel

• J. Gregory Modrall

  Dr. Modrall arrived at the University of Texas Southwestern Medical Center in July, 1998 after completing a clinical and research fellowship in Vascular Surgery at the University of Michigan Medical Center. He completed a residency in General Surgery at the University of Southern California School of Medicine in 1996. He completed research fellowships at the University of Southern California School of Medicine's Institute for Genetic Medicine in the Department of Biochemistry and Molecular Biology (1992-1994) and at the Jobst Vascular Research Laboratory of the University of Michigan Medical Center (1996-1997). He has a longstanding clinical and research interest in renovascular disease and has written manuscripts, reviews, and textbook chapters on the subject.

  Soon after arriving at the University of Texas Southwestern Medical Center, Dr. Modrall assembled his team of researchers and collaborators and opened the laboratory in January, 1999. The laboratory is now fully funded with extramural grants from the American Heart Association National Center.

• Chun-hua Yu, M.D.
  
  Dr. Yu is completed her medical training, including training in clinical nephrology in China.  She recently joined the Modrall Laboratory.

• Gerald Kramer, B.S.

Mr. Kramer is a veteran researcher, having served as a research associate in several laboratories over the past 20 years and publishing over 50 peer-reviewed articles.

Collaborators

• Mark C. Chappell, Ph.D.

  Dr. Chappell is an Associate Professor in the Hypertension and Vascular Disease Center at Wake Forest University. He has extensive experience related to hypertension research, especially in the role of the RAAS in hypertension. He is an invaluable collaborator for the laboratory.

Facilities

The laboratory is located at the Dallas Veterans Affairs Medical Center. A 500 square foot wet lab is fully equipped for all types of molecular and cellular research. Two cell culture incubators and a 6' hood for cell culture hoods are located nearby. The institutional animal facilities are located a short distance away in the same building.

Contact Information
J. Gregory Modrall, M.D.
Department of Surgery
University of Texas Southwestern Medical Center
5323 Harry Hines Blvd.
Dallas, TX 75390-9157
Office: (214) 857-1808
Lab: (214) 857-0935
FAX: (214) 857-1840
E-mail: greg.modrall@utsouthwestern.edu