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Anesthesiology

Houston, Texas

Baylor College of Medicine's Department of Anesthesiology is located in the heart of the Texas Medical Center
Anesthesiology
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Cerebrovascular Research Laboratory Faculty

Robert Bryan, Ph.D.
Professor
Vice Chair of Basic Science Research
Director of Cerebrovascular Research

Robert Bryan, Ph.D.

Research Interests

potassium channels, cerebral blood flow, traumatic brain injury

Current Posters

Neurotrauma 2007

Address

One Baylor Plaza, Suite 433D
Houston, TX, 77030
Tel: 713-798-7720
Fax: 713-798-7644
Email: rbryan@bcm.edu

Education

University of British Columbia, Canada:
Ph.D., 1980

Description of Research

Our interests center around the control of the cerebral circulation. We are studying the mechanism of a dilator process termed endothelium-derived hyperpolarizing factor (EDHF) or endothelium-dependent hyperpolarizations. EDHF, which is distinct from either nitric oxide or prostacyclin, may be protective following pathological conditions such as traumatic brain injury or stroke.

Additionally, we are studying a new type of potassium channels in cerebrovascular smooth muscle and endothelium. This new channel is termed tandem-pore domain potassium channels or K2P. Activation of potassium channels is associated with vessel dilation and an increase in cerebral blood flow. The K2P likely have an important, but presently unrecognized, role in the regulation of cerebral blood flow.

We are also studying the regulation of cerebral blood flow following traumatic brain injury (TBI). TBI is associated with dramatic decreases in cerebral blood flow. The mechanisms for the decrease in flow and the consequences are a major focus.

Selected Publications

  • Rogers PA, Chilian WM, Bratz IN, Bryan RM, Jr., Dick GM: H2O2 activates redox- and 4-aminopyridine-sensitive Kv channels in coronary vascular smooth muscle. AJP - Heart and Circulatory Physiology 2007; 292: H1404-H1411
  • Rogers PA, Chilian WM, Bratz IN, Bryan RM Jr., Dick GM: H2O2 activates redox- and 4-aminopyridine-sensitive Kv channels in coronary vascular smooth muscle.Am.J.Physiol Heart and Circulatory Physiology 292:H1404-H1411, 2007.
  • Marrelli SP, O'Neil RG, Brown RC, Bryan RM Jr.: PLA2 and TRPV4 channels regulate endothelial calcium in cerebral arteries.Am.J.Physiol Heart and Circulatory Physiology 292:H1390-H1397, 2007.
  • Bryan RM Jr., You J, Phillips SC, Andresen JJ, Lloyd EE, Rogers PA, Dryer SE, Marrelli SP: Evidence for two-pore domain potassium channels in rat cerebral arteries. Am.J.Physiol Heart and Circulatory Physiology 291:H770-H780, 2006.
  • Prisby RD, Wilkerson MK, Sokoya EM, Bryan RM Jr Wilson E, Delp MD: Endothelium-dependent vasodilation of cerebral arteries is altered with simulated microgravity through nitric oxide synthase and EDHF mechanisms. J.Appl.Physiol. 101:348-353 2006.
  • Andresen JJ, Shafi NI, Bryan RM Jr: Effects of carbon monoxide and heme oxygenase inhibitors in cerebral vessels of rats and mice. AJP - Heart and Circulatory Physiology 291:H223-H230, 2006.
  • Andresen J, Shafi NI, Bryan RM Jr: Endothelial influences on cerebrovascular tone. J.Appl.Physiol. 100:318-327 2006.
  • Jiang X, Yang F, Tan H, Liao D, Bryan RM Jr, Randhawa JK, Rumbaut RE, Durante W, Schafer AI, Yang X, Wang H: Hyperhomocystinemia impairs endothelial function and eNOS activity via PKC activation.Arterioscler.Thromb.Vasc Biol. 25:2515-2521. 2005.
  • Yang J, Clark JW, Bryan RM Jr, Roberson CS: Mathematical Modeling of the Nitric Oxide/cGMP Pathway in the Vascular Smooth Muscle Cell. American Journal of Physiology. Heart and Circulatory Physiology. 289(2):H886-97. Aug 2005.
  • Wilkerson MK, Lesniewski LA, Golding EM, Bryan RM Jr, Amin A, Wilson E, Delp MD: Simulated Microgravity Enhances Cerebral Artery Vasoconstriction and Vascular REsistence Through Endothelial Nitric Oxide Mechanism. Heart and Circulatory Physiology. 288(4):H1652-61. Apr 2005.
  • Bryan RM Jr: Endothelium-derived Hyperpolarizing Factor: a Cousin to Nitric Oxide and Prostacyclin. Anesthesiology.102(1261):1277. Published. 2005.
  • You J, Golding EM, Bryan RM Jr: Arachidonic Acid Metabolites, Hydrogen Peroxide, and EDHF in Cerebral Arteries. Heart and Circulatory Physiology. 289(H1077):H1083. 2005.
  • Yang J, Clark JW, Bryan RM Jr, Robertson CS: The Myogenic Response in Isolated Rat Cerebrovascular Arteries: Smooth Muscle Cell Model. Medical Engineering & Physics. 25(8):691-709. Oct 2003.
  • Yang J, Clark JW, Bryan RM Jr, Robertson CS: The Myogenic Response in Isolated Rat Cerebrovascular Arteries: Smooth Muscle Vessel Model. Medical Engineering & Physics. 25(8):711-7. Oct 2003.
  • Golding EM, Robertson CS, Fitch JC, Goodman JC, Bryan RM Jr Segmental Vascular Resistance After Mild Controlled Cortical Impact Injury in the Rat. Journal of Cerebral Blood Flow and Metabolism: Official Journal of the International Society of Cerebral Blood Flow and Metabolism. 23(2):210-8. Feb 2003.
  • Golding EM, Bryan RM Jr, Golding RM: The Effect of Surgery and Severe Injury on Blood Vessels. Physiological Measurement. 23(4):615-28. Nov. 2002.
  • Golding EM, Marrelli SP, You J, Bryan RM Jr: Endothelium-derived Hyperpolarizing Factor in the Brain: a New Regulator of Cerebral Blood Flow?. Stroke; a Journal of Cerebral Circulation. 33(3):661-3. Mar. 2002.
  • Schildmeyer LA, Bryan RM Jr: Effect of NO on EDHF Response in Rat Middle Cerebral Arteries. American Journal of Physiology. Heart and Circulatory Physiology. 282(2):H734-8. Feb. 2002.
  • Goodman JC, Feng YQ, Valadka AB, Bryan RM Jr, Robertson CS: Measurment of the Nitric Oxide Metabolites Nitrate and Nitrite in The Human Brain By Microdialysis. Acta Neurochirurgica. Supplement. 81:343-5. 2002.
  • Golding EM, You J, Robertson CS, Bryan RM Jr: Potentiated Endothelium-derived Hyperpolarizing Factor-mediated Dilations in Cerebral Arteries Following Mild Head Injury. Journal of Neurotrauma. 18(7):691-7. Jul. 2001.
  • Bryan RM Jr, Steenberg ML, Marrelli SP: Role of endothelium in shear stress-induced constrictions in rat middle cerebral artery. Stroke. 32(6):1394-400. Jun. 2001.
  • Bryan RM Jr, Marrelli SP, Steenberg ML, Schildmeyer LA, Johnson TD: Effects of luminal shear stress on cerebral arteries and arterioles. American Journal of Physiology. Heart and Circulatory Physiology. 280(5):H2011-22. May. 2001.
  • You J, Edvinsson L, Bryan RM Jr: Neuropeptide Y-mediated constriction and dilation in rat middle cerebral arteries. Journal of Cerebral Blood Flow and Metabolism. 21(1):77-84. Jan. 2001.
  • Golding EM, Steenberg ML, Johnson TD, Bryan RM Jr: Nitric Oxide in the Potassium-induced Response of the Rat Middle Cerebral Artery: a Possible Permissive Role.. Brain Research. 889(1-2):98-104. Jan 2001.
  • Golding EM, Robertson CS, Bryan RM Jr: L-arginine partially restores the diminished CO2 reactivity after mild controlled corical impact injury in the adult rat. Journal of Cerebral Blood Flow and Metabolism. 20(5):820-8. May. 2000.
  • Giri BK, Krishnappa IK, Bryan RM Jr, Robertson CS, Watson J: Regional cerebral blood flow after cortical impact injury by a secondary insult in rats. Stroke. 31(4):961-7. Apr. 2000.
  • Zubkov AY, Rollins KS, Parent AD, Zhang J, Bryan RM Jr: Mechanism of endothelin-l-induced contraction in rabbit basilar artery-Editorial Comment. Stroke. 31:526-533. Jan. 2000.
  • Hirschfield W, Moody MR, O'Brien WE, Gregg AR, Bryan RM Jr, Reid MB: Nitric oxide release and contractile properties of skeletal muscles from mice deficient in type III NOS. American Journal of Physiology. 278:R95-R100. 2000.
  • Golding EM, Steenberg ML, Johnson TD, Bryan RM Jr: The effects of potassium on the rat middle cerebral artery. Brain Research. 880:159-166. 2000.
  • Mathew BP, DeWitt DS, Bryan RM Jr, Bukoski RD, Prough DS: Traumatic brain injury reduces myogenic responses in pressurized rodent middle cerebral arteries. Journal of Neurotrauma. 16(12):1177-86. Dec. 1999.
  • Golding EM, Steenberg ML, Contant CF Jr, Krishnappa I, Robertson CS, Bryan RM Jr: Cerebrovascular reactivity to CO2 and hypotension after mild cortical impact injury. American Journal of Physiology. 277(4 Pt 2):H1457-66. Oct. 1999.
  • You J, Johnson TD, Marrelli SP, Bryan RM Jr: Functional heterogeneity of endothelial P2 purinoceptors in the cerebrovascular tree of the rat.. American Journal of Physiology. 277(3 Pt 2):H893-900. Sep. 1999.
  • You J, Johnson TD, Marrelli SP, Mombouli JV, Bryan RM Jr: P2u receptor-mediated release of endothelium-derived relaxing factor/nitric oxide and endothelium-derived hyperpolarizing factor from cerebrovascular endothelium in rats. Stroke. 30(5):1125-33. May 1999.
  • Golding EM,Robertson CS,Bryan RM Jr,The consequences of traumatic brain injury on cerebral blood flow and autoregulation: a review.Clinical and Experimental Hypertension. 21(4):299-332. May 1999.
  • Marrelli SP, Khorovets A, Johnson TD, Childres WF, Bryan RM Jr,P2 purinoceptor-mediated dilations in the rat middle cerebral artery after ischemia-reperfusion. American Journal of Physiology. 276(1 Pt 2):H33-41. Jan 1999.
  • Golding EM, Contant CF Jr, Robertson CS, Bryan RM Jr,Temporal effect of severe controlled cortical impact injury in the rat on the myogenic response of the middle cerebral artery. Journal of Neurotrauma. 15(11):973-84. November 1998.
  • Golding EM, Steenberg ML, Cherian L, Marrelli SP, Robertson CS, Bryan RM Jr,Endothelial-mediated dilations following severe controlled cortical impact injury in the rat middle cerebral artery. Journal of Neurotrauma. 15(8):635-44. August 1998.
  • Swafford MW, Raty S, Childres WF, Bryan RM Jr,Effect of decreased glucose concentration on cerebrovascular tone in vitro. Journal of Cerebral Blood Flow and Metabolism. 18(4):391-5. April 1998.
  • Golding EM, S Robertson C, Bryan RM Jr,Comparison of the myogenic response in rat cerebral arteries of different calibers. Brain Research. 785(2):293-8. March 1998.
  • Johnson TD, Marrelli SP, Steenberg ML, Childres WF, Bryan RM Jr,Inward rectifier potassium channels in the rat middle cerebral artery. American Journal of Physiology. 274(2 Pt 2):R541-7. February 1998.
  • Wang Q,Bryan, RM, Jr.,Pelligrino DA,Calcium-dependent and ATP-sensitive potassium channels and the 'permissive' function of cyclic GMP in hypercapnia-induced pial arteriolar relaxation. Brain Research. 793:187-196. 1998.
  • You J, Johnson TD, Childres WF, Bryan RM Jr,Endothelial-mediated dilations of rat middle cerebral arteries by ATP and ADP. American Journal of Physiology. 273(3 Pt 2):H1472-7. September 1997.
  • Ignacio CS, Curling PE, Childres WF, Bryan RM Jr,Nitric oxide-synthesizing perivascular nerves in the rat middle cerebral artery. American Journal of Physiology. 273(2 Pt 2):R661-8. August 1997.
  • Bryan RM Jr, Eichler MY, Swafford MW, Johnson TD, Suresh MS, Childres WF,Stimulation of alpha 2 adrenoceptors dilates the rat middle cerebral artery. Anesthesiology. 85(1):82-90. July 1996.
  • Johnson TD, Childres WF, Bryan RM Jr,The in vitro action of polyamines on rat basilar and femoral artery contractile activity. Life Sciences. 59(7):529-36. 1996.
  • Bryan RM Jr, Steenberg ML, Eichler MY, Johnson TD, Swafford MW, Suresh MS,Permissive role of NO in alpha 2-adrenoceptor-mediated dilations in rat cerebral arteries. American Journal of Physiology. 269(3 Pt 2):H1171-4. September 1995.
  • Bryan RM Jr, Duckrow RB,Radial columns in autoradiographs generated from tracer methods for measuring cerebral cortical blood flow. American Journal of Physiology. 269(2 Pt 2):H583-9. August 1995.
  • Bryan RM Jr, Cherian L, Robertson C,Regional cerebral blood flow after controlled cortical impact injury in rats. Anesthesia and Analgesia. 80(4):687-95. April 1995.
  • Goodman JC, Cherian L, Bryan RM Jr, Robertson CS,Lateral cortical impact injury in rats: pathologic effects of varying cortical compression and impact velocity. Journal of Neurotrauma. 11(5):587-97. October 1994.
  • Cherian L,Robertson CS,Contant CF, Jr.,Bryan, RM, Jr,Lateral cortical impact injury in rats: Cerebrovascular effects of varying depth of cortical deformation and impact velocity. Journal of Neurotrauma. 11:573-586. 1994.
  • Bryan RM Jr, Eichler MY, Johnson TD, Woodward WT, Williams JL,Cerebral blood flow, plasma catecholamines, and electroencephalogram during hypoglycemia and recovery after glucose infusion. Journal of Neurosurgical Anesthesiology. 6(1):24-34. January 1994.
  • Pelligrino DA, LaManna JC, Duckrow RB, Bryan RM Jr, Harik SI,Hyperglycemia and blood-brain barrier glucose transport. Journal of Cerebral Blood Flow and Metabolism. 12(6):887-99. November 1992.
  • Williams JL, Jones SC, Page RB, Bryan RM Jr,Vascular responses of choroid plexus during hypercapnia in rats. American Journal of Physiology. 260(6 Pt 2):R1066-70. June 1991.
  • Ringel M,Bryan RM Jr,Vannucci R C,Regional cerebral blood flow during hypoxia-ischemia in the immature rat: comparison of iodoantipyrine and iodoamphetamine as radioactive tracers. Brain research. Developmental Brain Research. 59(2):231-5. 24 Apr 1991.
  • Bryan RM Jr Jr,Cerebral blood flow and energy metabolism during stress. American Journal of Physiology. 259(2 Pt 2):H269-80. August 1990.
  • Page R B,Gropper M,Woodard E,Townsend J,Davis S,Bryan RM Jr,Role of catecholamines in regulating ovine median eminence blood flow.. American Journal of Physiology. 258(5 Pt 2):R1242-9. May 1990.
  • Xing L P,King J C,Bryan RM Jr,Kauffman G L Jr,Effect of neurotensin on regional cerebral glucose utilization in cold water-restrained rats. American Journal of Physiology. 258(4 Pt 1):G591-5. April 1990.
  • Bryan RM Jr, Pelligrino DA,Cerebral blood flow during chronic hypoglycemia in the rat. Brain Research. 475(2):397-400. December 1988.
  • MacNeill C, Bryan RM Jr,Regional cerebral glucose utilization transiently increases during mild hypoxia. Journal of Cerebral Blood Flow and Metabolism. 8(4):495-501. August 1988.
  • Bryan RM Jr, Myers CL, Page RB,Regional neurohypophysial and hypothalamic blood flow in rats during hypercapnia. American Journal of Physiology. 255(2 Pt 2):R295-302. August 1988.
  • Bryan RM Jr, Lehman RA,Cerebral glucose utilization after aversive conditioning and during conditioned fear in the rat. Brain Research. 444(1):17-24. March 1988.
  • Wurpel JN, Dundore RL, Bryan RM Jr, Keil LC, Severs WB,Regional cerebral glucose utilization during vasopressin-induced barrel rotations or bicuculline-induced seizures in rats. Pharmacology. 36(1):1-8. 1988.
  • Hollinger BR, Bryan RM Jr,Beta-receptor-mediated increase in cerebral blood flow during hypoglycemia. American Journal of Physiology. 253(4 Pt 2):H949-55. October 1987.
  • Duckrow RB, Bryan RM Jr,Regional cerebral glucose utilization during hyperglycemia. Journal of Neurochemistry. 48(3):989-93. March 1987.
  • Bryan RM Jr, Hollinger BR, Keefer KA, Page RB,Regional cerebral and neural lobe blood flow during insulin-induced hypoglycemia in unanesthetized rats. Journal of Cerebral Blood Flow and Metabolism. 7(1):96-102. February 1987.
  • Bryan RM Jr,A method for measuring regional cerebral blood flow in freely moving, unstressed rats. Journal of Neuroscience Methods. 17(4):311-22. September 1986.
  • Bryan RM Jr, Jobsis FF,Insufficient supply of reducing equivalents to the respiratory chain in cerebral cortex during severe insulin-induced hypoglycemia in cats. Journal of Cerebral Blood Flow and Metabolism. 6(3):286-91. June 1986.
  • Bryan RM Jr, Keefer KA, MacNeill C,Regional cerebral glucose utilization during insulin-induced hypoglycemia in unanesthetized rats. Journal of Neurochemistry. 46(6):1904-11. June 1986.
  • Townsend JB, Ziedonis DM, Bryan RM Jr, Brennan RW, Page RB,Choroid plexus blood flow: evidence for dopaminergic influence. Brain Research. 290(1):165-9. January 1984.
  • Bryan RM Jr, Jobsis FF,The cerebral redox state in cats during severe insulin induced hypoglycemia. Brain Research. 279(1-2):266-70. November 1983.
  • Mans AM, Biebuyck JF, Davis DW, Bryan RM Jr, Hawkins RA,Regional cerebral glucose utilization in rats with portacaval anastomosis. Journal of Neurochemistry. 40(4):986-91. April 1983.
  • Bryan RM Jr, Hawkins RA, Mans AM, Davis DW, Page RB,Cerebral glucose utilization in awake unstressed rats. American Journal of Physiology. 244(3):C270-5. March 1983.
  • Bryan RM Jr, Jones DR,Cerebral energy metabolism in mallard ducks during apneic asphyxia: the role of oxygen conservation. American Journal of Physiology. 239(3):R352-7. September 1980.
  • Bryan RM Jr, Jones DR,Cerebral energy metabolism in diving and non-diving birds during hypoxia and apnoeic asphyxia. Journal of Physiology. 299:323-36. February 1980.

August 9, 2007