JONATHAN H. JAGGAR, Ph.D.

Associate Professor

Department of Physiology

The University of Tennessee College of Medicine

Address

The University of Tennessee Health Science Center

894 Union Avenue

Memphis, TN 38163

Tel: (901) 448-1208;

Lab: 413 Nash Research Building

Education

Ph.D. Institution: University of Sheffield, United Kingdom

Research Interests

Arterial diameter, a primary determinant of systemic blood pressure, is regulated by the contractile state of smooth muscle cells in the arterial wall. One critical regulator of smooth muscle contractility is the intracellular calcium ion concentration. Smooth muscle cells control intracellular calcium concentration by regulating cellular influx, release, sequestration and extrusion. Since membrane potential regulates calcium entry in smooth muscle cells, ion channels that modulate membrane potential also change cellular contractility. Recent studies have discovered that local and global elevations in cytosolic calcium occur in smooth muscle cells. These different calcium signaling events not only regulate contractility, but may also regulate a number of other physiological functions. We are currently investigating sarcolemma ion channels that control membrane potential and calcium entry in arterial smooth muscle cells and the properties, physiological targets, and regulation of arterial diameter by different intracellullar calcium signals. Research in the laboratory involves a multi-faceted approach, studying events at molecular, cellular and intact artery levels. Techniques include patch clamp electrophysiology, rapid confocal calcium imaging, conventional calcium imaging, diameter measurement of pressurized arteries, and molecular biology.

Links

Physiology - Jonathan H. Jaggar

Recent Publications

• Zhao G, Adebiyi A, Blaskova E, Xi Q, Jaggar JH. Type 1 inositol 1,4,5-trisphosphate receptors mediate UTP-induced cation currents, Ca2+ signals, and vasoconstriction in cerebral arteries. Am J Physiol Cell Physiol. 2008 Nov;295(5):C1376-84. Epub 2008 Sep 17. PMID: 18799650
• Adebiyi A, McNally EM, Jaggar JH. Sulfonylurea receptor-dependent and -independent pathways mediate vasodilation induced by ATP-sensitive K+ channel openers. Mol Pharmacol. 2008 Sep;74(3):736-43. Epub 2008 May 29. PMID: 18511652
• Xi Q, Adebiyi A, Zhao G, Chapman KE, Waters CM, Hassid A, Jaggar JH. IP3 constricts cerebral arteries via IP3 receptor-mediated TRPC3 channel activation and independently of sarcoplasmic reticulum Ca2+ release. Circ Res. 2008 May 9;102(9):1118-26. Epub 2008 Apr 3. PMID: 18388325
• Li A, Xi Q, Umstot ES, Bellner L, Schwartzman ML, Jaggar JH, Leffler CW. Astrocyte-derived CO is a diffusible messenger that mediates glutamate-induced cerebral arteriolar dilation by activating smooth muscle Cell KCa channels. Circ Res. 2008 Feb 1;102(2):234-41. Epub 2007 Nov 8. PMID: 17991880
• Cheng X, Liu J, Asuncion-Chin M, Blaskova E, Bannister JP, Dopico AM, Jaggar JH. A novel Ca(V)1.2 N terminus expressed in smooth muscle cells of resistance size arteries modifies channel regulation by auxiliary subunits. J Biol Chem. 2007 Oct 5;282(40):29211-21. Epub 2007 Aug 14. PMID: 17699517
• Jaggar JH. Smooth muscle sparklet Ca(v) channels defined: 1.2 is the number. Am J Physiol Heart Circ Physiol. 2007 Sep;293(3):H1317-9. Epub 2007 Jun 1. No abstract available. PMID: 17545476

view complete list of references (pubmed link)