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Joshua S. Speed, PhD

Joshua S. Speed, PhD
Department of Medicine
Division of Nephrology
University of Alabama at Birmingham
1720 2nd Ave. S.
Kaul 868
Birmingham, AL 35294 USA
Phone: 205-934-2430
Fax: 205-975-7520



  • 2001-2005
    B. S., Belhaven College, Jackson, MS,    Major:  Chemistry, Minor: Mathematics
  • 2006-2011
    Ph.D., University of Mississippi Medical Center, Jackson, MS, Physiology and Biophysics
  • 2011-2013
    Postdoctoral Fellow, Section of Experimental Medicine, Georgia Regents University, Augusta, GA
  • 2014-2015
    Postdoctoral Fellow, Cardio-Renal Medicine and Physiology, University of Alabama at Birmingham, Birmingham, AL

Research Interests:

The main focus of my research revolves around pathophysiology associated with high salt diet and the importance of endothelin-1 to promote salt homeostasis and maintain normal blood pressure. Currently, my research focuses on renal circadian rhythms and the mechanisms related to diurnal blood pressure variation. Non-dipping of blood pressure is a major risk factor for cardiovascular disease, therefore my research is aimed at elucidating the mechanisms and dietary factors that influence blood pressure rhythms.

More recently, I have become interested in how elevations in salt intake can promote the development of obesity. High salt intake, a common component of a Western diet, stimulates the production of endothelin-1 (ET-1) by the endothelium. ET-1 receptors located on adipocytes can have a major impact on lipid metabolism, depending on the receptor subtype that is activated, ETA or ETB. The current hypothesis is that an imbalance of ET-1 receptor signaling can promote the development of obesity, especially since salt intake among the population is well above recommended levels. Currently, these studies are funded by a K99/R00 that activated in January 2016.


  1. LaMarca, BB, Speed JS, Fournier L, Cockrell K, Granger JP. Angiotensin II Type I Receptor Blockade Prevents Interleukin (IL-6)-Induced Hypertension in the Pregnant Rat. Hypertension 48:(4); e47, 2006
  2. Granger JP, Abram S, Stec D, Chandler D, Speed JS, LaMarca BB. Endothelin, the Kidney, and Hypertension. Current Hypertension Reports, 2006; 8:298-303.
  3. Jernigan NK, LaMarca BB, Speed JS, Galmiche L, Granger JP, Drummond HA. Dietary salt enhances benzamil sensitive component of myogenic constriction in mesenteric arteries. Am J Physiol:Heart Physiol 294: H409–H420, 2008.
  4. LaMarca B, Speed JS, Babcock S, Berry H, Cockrell K, Gilbert JS, Granger JP. Hypertension in response to chronic reductions in uterine perfusion in pregnant rats: Effect of TNF-alpha blockade. Hypertension. 2008 Dec; 52(6):1161-7
  5. Jernigan N, Speed JS, LaMarca BB, Granger JP Drummond H. Angiotensin II regulation of renal vascular ENaC proteins. Am J Hypertension. 2009 Jun; 22(6):593-7
  6. Chandler DL, Llinas MT, Reckelhoff JF, LaMarca B, Speed JS, Granger JP. Effects of hyperhomocysteinemia on arterial pressure and nitric oxide production in pregnant rats. Am J Hypertens. 2009 Oct;22 (10):1115-9.
  7. Young S, Storm M, Speed JS, Kelsen S, Tiller C, Vera T, Drummond H, Stec D. Inhibition of Biliverdin Reductase Increases Angiotensin II-Dependent Superoxide Levels in Cultured Renal Tubular Epithelial Cells. Am J Physiol Regul Integr Comp Physiol. 2009 Nov, 297 (5): R1546-53
  8. Tam Tam KB, George E, Cockrell K, Arany M, Speed JS, Martin JN Jr, Lamarca B, Granger JP. Endothelin type A receptor antagonist attenuates placental ischemia-induced hypertension and uterine vascular resistance. Am J Obstet Gynecol. 2011 Apr;204 (4):330.e1-4
  9. Speed JS, Lamarca B, Berry H, Cockrell K, George EM, Granger JP. Renal Medullary Endothelin-1 is Decreased in Dahl Salt Sensitive Rats. Am J Physiol Regul Integr Comp Physiol. 2011 Aug; 301(2):R519-23
  10. Speed JS, George EM, Arany M, Cockrell K, and Granger JP. Role of 20-Hydroxyeicosatetraenoic Acid in Mediating Hypertension in Response to Chronic Renal Medullary Endothelin Type B Receptor Blockade. PLoS One. 2011;6(10):e26063
  11. Hall JE, Granger JP, do Carmo J, da Silva A, Dubinion J, George E, Hamza S, Speed JS, Hall M. Hypertension: Physiology and Pathophysiology. Compr Physiol. 2012 Oct;2(4):2393-442.
  12. Hyndman KA, Xue J, Macdonell A, Speed JS, Jin C, Pollock JS. Distinct Regulation of Inner Medullary Collecting Duct NO Production from Rats and Mice. Clin Exp Pharmacol Physiol. 2013. Jan 21. Epub
  13. Speed JS, Pollock DM. Endothelin, Kidney Disease, and Hypertension. Hypertension. 2013 Jun;61(6):1142-5.
  14. Jin C*, Speed JS*, Hyndman KA, O’Connor PA, Pollock DM. Sex Differences in ET-1 Receptor Expression and Ca2+ Signaling in the IMCD. Am J Physiol Renal Physiol. 2013 Oct 15;305(8):F1099-104. *Authors contributed equally to the preparation of this manuscript.
  15. Heimlich JB, Speed JS, Bloom CJ, O'Connor PM, Pollock JS, Pollock DM. ET-1 increases reactive oxygen species following hypoxia and high-salt diet in the mouse glomerulus. Acta Physiol. 2015 Mar; 213(3):722-30.
  16. Speed, JS, D’Angelo G, Wach PA, Sullivan JC, Pollock JS, Pollock DM. High salt diet increases the pressor response to stress in female, but not male ETB deficient rats. Physiol Rep. 2015 Mar;3(3)
  17. Speed JS, Fox BM, Johnston J, Pollock DM. Endothelin and Renal Ion and Water Transport. Semin Nephrol. 2015 Mar;35(2):137-144
  18. Heimlich, JB, Speed JS, O’Connor PM, Townes T, Meiler SE, Kutlar A, Pollock JS, Pollock DM. Endothelin-1 contributes to the progression of renal injury in sickle cell disease via reactive oxygen species. Brit J Pharm. 2015 Nov 12.
  19. Speed, JS, Heimlich JB, Saleh MA, Hyndman KA, Pollock JS, Pollock DM. Evidence for ETB-dependent regulation of circadian blood pressure during high salt feeding in the rat. (Under Review; Am J Physiol: Renal Physiol)
  20. Speed, JS, Heimlich JB, Hyndman KA, Patel VH, Yanagisawa M, Pollock JS, Titze JM, Pollock DM. Endothelin as a master regulator of whole body Na+ Homeostasis. FASEB J. 2015 Dec;29(12):4937-44.
  21. De Miguel C, Speed JS, Kasztan M, Gohar EY, Pollock DM. Endothelin-1 and the kidney: new perspectives and recent findings. Curr Opin Nephrol Hypertens.2016 Jan;25(1):35-41.
  22. Speed, JS and Pollock DM. New clues towards solving the mystery of endothelin and blood pressure regulation. Hypertension 2015 Aug;66(2):275-7.
  23. Jin, C, Speed JS, Pollock DM. High salt intake increases endothelin B receptor function in the renal medulla. Life Sciences. (In Press)
  24. Speed, JS and Hyndman KA. In vivo organ specific drug delivery with implantable peristaltic pumps. Scientific Reports (In Press)