Salt-sensitivity or salt-dependent elevations in blood pressure are evident in a majority of the human population. Renal defects in the control of sodium excretion are known to be major contributors to the development of salt-dependent hypertension. Work conducted by each of the Project Leaders over the past 10 years has provided important Information about the powerful role of the renal endothelin (ET- 1) system in the control of sodium excretion, renal hemodynamics, and blood pressure indicating that the endothelin system rivals the renin-angiotensin system in physiological significance. This includes important evidence that a high salt diet, even without hypertension, has a significant influence on renal hemodynamic function. Our studies have led us to hypothesize that the ETB receptor functions as a counter-balance to the powerful vasoconstrictor and pro-hypertensive actions of the ETA receptor. However, there is simply not enough information available about the specific conditions that determine the activity of these receptor systems. The current proposal builds on studies demonstrating that the ETA receptor plays a role in promoting hypertension and associated end-organ damage while a lack of ETB receptor function results in increased sensitivity to salt-induced hypertension. Therefore, the goal of the current Program Project is to determine the physiological actions of ET-1 using an array of experimental approaches ranging from the gene level to whole animal models to comprehensively explore the pathways regulating ET-1 activity in the kidney. The current Program is made of four Projects. Each project explores a unique aspect of the endothelin system in terms of both hemodynamics and tubular function and will elucidate the receptor subtype specific actions on inflammation, oxidative stress, renal hemodynamics and tubular function;a particular emphasis is on factors that influence the control of sodium excretion and blood pressure. These studies are expected to provide important new insight into a major system that regulates renal sodium excretion. In particular, this Program will investigate a full range of mechanisms that control ET-1 release and receptor specific actions in order to provide clinically relevant information.

Public Health Relevance

The Program Project focuses on elucidating mechanisms by which the kidney controls sodium excretion, and therefore, has direct relevance to the serious health problem of salt-dependent hypertension and kidney disease. This Program will investigate a new pathway, the endothelin system, which plays a major role in the control of renal function and blood pressure. These studies also could contribute to novel therapeutic approaches given the current use and development of endothelin antagonists in humans.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Program Projects (P01)
Project #
5P01HL095499-04
Application #
8464198
Study Section
Heart, Lung, and Blood Initial Review Group (HLBP)
Program Officer
Maric-Bilkan, Christine
Project Start
2010-08-06
Project End
2015-04-30
Budget Start
2013-05-01
Budget End
2014-04-30
Support Year
4
Fiscal Year
2013
Total Cost
$2,136,145
Indirect Cost
$512,805
Name
Georgia Regents University
Department
Surgery
Type
Schools of Medicine
DUNS #
966668691
City
Augusta
State
GA
Country
United States
Zip Code
30912
Osmond, David A; Zhang, Shali; Pollock, Jennifer S et al. (2014) Clopidogrel preserves whole kidney autoregulatory behavior in ANG II-induced hypertension. Am J Physiol Renal Physiol 306:F619-28
Pollock, David M (2014) 2013 Dahl Lecture: American Heart Association council for high blood pressure research clarifying the physiology of endothelin. Hypertension 63:e110-7
Fellner, Robert C; Cook, Anthony K; O'Connor, Paul M et al. (2014) High-salt diet blunts renal autoregulation by a reactive oxygen species-dependent mechanism. Am J Physiol Renal Physiol 307:F33-40
Kohan, Donald E; Barton, Matthias (2014) Endothelin and endothelin antagonists in chronic kidney disease. Kidney Int 86:896-904
Guan, Zhengrong; Singletary, Sean T; Cook, Anthony K et al. (2014) Sphingosine-1-phosphate evokes unique segment-specific vasoconstriction of the renal microvasculature. J Am Soc Nephrol 25:1774-85
Hyndman, Kelly A; Ho, Dao H; Sega, Martiana F et al. (2014) Histone deacetylase 1 reduces NO production in endothelial cells via lysine deacetylation of NO synthase 3. Am J Physiol Heart Circ Physiol 307:H803-9
Donato, Anthony J; Lesniewski, Lisa A; Stuart, Deborah et al. (2014) Smooth muscle specific disruption of the endothelin-A receptor in mice reduces arterial pressure, and vascular reactivity and affects vascular development. Life Sci 118:238-43
Jin, Chunhua; Jeon, Yejoo; Kleven, Daniel T et al. (2014) Combined endothelin a blockade and chlorthalidone treatment in a rat model of metabolic syndrome. J Pharmacol Exp Ther 351:467-73
Kittikulsuth, W; Sullivan, J C; Pollock, D M (2013) ET-1 actions in the kidney: evidence for sex differences. Br J Pharmacol 168:318-26
Hyndman, Kelly A; Xue, Jing; MacDonell, Alexander et al. (2013) Distinct regulation of inner medullary collecting duct nitric oxide production from mice and rats. Clin Exp Pharmacol Physiol 40:233-9

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