Physiology Staff

Dr James Todd Pearson
Senior Research Fellow (Monash University)
BSc (Hons), PhD (Adelaide)

Monash Centre for Synchrotron Science &
Department of Physiology

Address
Department of Physiology
Monash University VIC 3800
Australia

Located
Room F228, Building 13F (Physiology) at Clayton Campus
and
Monash Center for Synchrotron Science
Building 220, 770 Blackburn Rd
Monash University

Tel: +61 3 990 29783
Email: James.Pearson@monash.edu

Background

Dr Pearson obtained his PhD from the Department of Zoology (now School of Environmental Sciences), University of Adelaide in 1995. He then spent nearly 10 years in postdoctoral positions in Japan. In 2005 he moved from the Department of Cardiac Physiology, National Cardiovascular Center Research Institute in Osaka, Japan, to Monash to take up a Monash Synchrotron Fellowship. Since 2001 his notable area of expertise has been the application of synchrotron techniques to the study of in vivo physiology. In this time Dr Pearson and his colleagues have consistently been awarded access on a merit basis to the world’s largest synchrotron at SPring-8 (Hyogo Prefecture of southern Japan). This fundamental cardiovascular research using living small animal models has involved scientists and clinicians from Japan, Australia and New Zealand. More recently, these collaborations have broadened to incorporate the fields of engineering and physics. With the commissioning of the Australian Synchrotron at Clayton in 2008 it is expected that much of this research will now be conducted here in Melbourne, with greater access to novel animal models, molecular biology approaches and young research students and postdocs.

Research Interests

• Synchrotron x-ray imaging

• Contrast absorption imaging of the vasculature in healthy and chronic disease states
• Phase contrast imaging of lung congestion
• Novel contrast agents for vascular imaging

• Synchrotron muscle diffraction

• Dynamic whole heart studies in situ and in real time
• Investigating the molecular basis of contractility increases (positive inotropy)
• Understanding the mechanisms of therapies to treat chronic heart failure

• Application of radiotelemetry

• The roles of neuromodulators in autonomic control of cardiovascular function
• Central and peripheral chemoreflexes and the coupling of respiration and heart rate

• Left ventricle pressure-volumetry

• Regulation of LV contractile function at the whole-heart level and the effects of heart failure
• Adenosine agonist therapies to prevent heart failure

Dr Pearson utilizes synchrotron radiation in two different ways to perform functional imaging of live animals. First, the circulation to organ systems such as the brainstem, lung, heart and kidney and their control mechanisms are being investigated with high resolution contrast angiography in combination with pharmacological techniques that stimulate or prevent vasomotor control mechanisms. In collaboration with colleagues in Mechanical Engineering better image analysis techniques are now being developed (Fig. 1). In doing so it is expected that this high resolution imaging (spatial and temporal resolution) will provide a new perspective on the root causes of hypertension and microvascular dysfunction in chronic heart failure. Second, he has a unique research program that implements an X-ray diffraction technique to investigate the force generating process of cardiac muscle, by real time appraisal of cross-bridge dynamics in the left ventricle wall of the intact, beating heart. This technique when conducted simultaneous to conventional pressure-volume loop analyses provides an opportunity to examine important regulatory pathways including the Frank-Starling Law of the Heart, cardiac force-frequency relation and the all important b–adrenoceptor pathway. It is expected that this information will better help to understand the cellular mechanisms involved in cardiac hypertrophy and heart failure.

Figure 2 (shown right). Shows the rapid diffraction recordings obtained from a beating heart with respect to muscle layer of the anterior wall. From the reflections scattered about the centre of each image it is possible to calculate indices of cross-bridge cycling and myofilament spacing in real time (Reproduced with permission of The Biophysical Society © 2007, Biophys. J. Online http://www.biophysj.org/). For further details see publication 12).

Collaborators include

• Prof. Mikiyasu Shirai, Hiroshima International University, Japan
• Prof. Naoto Yagi, Japan Synchrotron Radiation Research Institute (SPring-8)
• Dr Keiji Umetani, Japan Synchrotron Radiation Research Institute (SPring-8)
• Dr Daryl Schwenke, Otago University, New Zealand
• The Cardiovascular and Renal Physiology Group
• Division of Biological Engineering, Monash

Current Service

• Editorial Board, Clinical and Experimental Pharmacology & Physiology
• Local organising Committee for Medical Applications of Synchrotron Radiation 2010 International Meeting
• Lecturer in Science, Physiotherapy and Radiology Courses
• Beamline Advisory Panel at the Imaging & Therapy Beamline, Australian Synchrotron
  

Recent Funding

• 2009, NH&MRC Enabling Grant (606959). $13.2 million. , JT Pearson, D Häusermann, R Lewis and AI Smith. Imaging and Medical Therapy Beamline for the Australian Synchrotron.
• 2009, Strategic Collaborative Grant, Faculty of Medicine, Nursing and Health Sciences, Monash University. $54,000. RG Evans, JT Pearson, P Andrews, M Massimiliano, D Lo Jacono, K Hourigan. A new approach to the study of renal vascular function using synchrotron based angiography
• 2009, Australian Research Council LIEF grant (LE0989341). $690,000. F Caruso, K Hourigan, GW Stevens, T Sridhar, SJ Kent, A Fouras,GG Qiao, DE Dunstan, GA Thouas, SB Hooper, AJ O’Connor, AP Johnston, BM Stadler, RG Evans, SL Gras, KM Denton, JT Pearson, GK Such, A Blencowe, MJ Kitchen, KK Siu. Advanced NanoBiomaterials Imaging Facility.
• 2008, Australian Research Council discovery grant (DP0877327). $340,000. K Hourigan, MC Thompson, SB Hooper, JT Pearson, RG Evans, KM Denton, T Leweke. Engineering imaging and supercomputer prediction of biofluid flows.
• 2008, Australian Nuclear Science & Technology Organisation, AMRF program travel grant. $9,300. JT Pearson, AJ Edgley. Investigating the benefits of selective adenosine A2a agonists in the prevention of endothelial dysfunction after myocardial infarction.
• 2006, Australian Research Council LIEF grant (LE0668435). $1.3 million. T Sridar, W Anderson, F Caruso, J Bertram, J Friend, I Harper, L Teo, R Evans, G Forde, H Parkington, R Jagadeeshan, B Oldfield, J Carberry, J Pearson, J Sheridan, M Thompson. Biomedical Engineering Sensing and Imaging Facility.
• 2006, Australian Nuclear Science & Technology Organisation, AMRF program travel grant. $8,000. JT Pearson, GA Eppel, AJ Edgley. Investigating regional differences in heart in situ cross-bridge cycling during transient pressure increases in the infarcted heart.
• 2006, ANZ Medical Trustees – Dean Robert Winter Trust, Equipment Grant. $20,000.     JT Pearson. Synchrotron investigations into cardiac ischaemia-reperfusion injury.

Recent Publications

1. Hanada, R., H. Teranishi, J. T. Pearson, M. Kurokawa, H. Hosoda, N. Fukushima, Y. Fukue, R. Serino, H. Fujihara, Y. Ueta, M. Ikawa, M. Okabe, N. Murakami, M. Shirai, H. Yoshimatsu, K. Kangawa and M. Kojima. (2004). Neuromedin U has a novel anorexigenic effect independent of the leptin signaling pathway. Nature Medicine 10, 1067-73.
2. Pearson, J. T., M. Shirai, H. Ito, N. Tokunaga, H. Tsuchimochi, N. Nishiura, D. O. Schwenke, H. Ishibashi-Ueda, R. Akiyama, H. Mori, K. Kangawa, H. Suga and N. Yagi. (2004). In situ measurements of crossbridge dynamics and lattice spacing in rat hearts by x-ray diffraction: sensitivity to regional ischemia. Circulation 109, 2976-9.
3. Seymour, R. S., S. Runciman, R. V. Baudinette and J. T. Pearson. (2004). Developmental allometry of pulmonary structure and function in the altricial Australian pelican Pelecanus conspicillatus. Journal of Experimental Biology 207, 2663-9.
4. Runciman, S., R. S. Seymour, R. V. Baudinette and J. T. Pearson. (2005). An allometric study of lung morphology during development in the Australian pelican, Pelicanus conspicillatus, from embryo to adult. Journal of Anatomy 207, 365-380.
5. Schwenke, D. O., J. T. Pearson, H. Tsuchimochi, H. Mori and M. Shirai. (2005). Exogenous nitric oxide centrally enhances pulmonary reactivity in the normal and hypertensive rat. Clinical and Experimental Pharmacology and Physiology 32, 952-959.
6. Kogata, N., Y. Arai, J. T. Pearson, K. Hashimoto, K. Hidaka, T. Koyama, S. Somekawa, Y. Nakaoka, M. Ogawa, R. H. Adams, M. Okada and N. Mochizuki. (2006). Cardiac ischemia activates vascular endothelial cadherin promoter in both preexisting vascular cells and bone marrow cells involved in neovascularization. Circulation Research 98, 897-904.
7. Schwenke, D. O., J. T. Pearson, H. Mori and M. Shirai. (2006). Long-term monitoring of pulmonary arterial pressure in conscious, unrestrained mice. Journal of Pharmacological & Toxicological Methods 53, 277-283.
8. Schwenke, D. O., J. T. Pearson, H. Mori and M. Shirai. (2006). Does central nitric oxide elicit pulmonary hypertension in conscious rats? Respiratory Physiology & Neurobiology 153, 250-260.
9. Schwenke, D. O., J. T. Pearson and M. Shirai. (2006). Does central nitric oxide chronically modulate the acute hypoxic ventilatory response in conscious rats? Acta Physiologica Scandinavica 186, 309-318. Pearson, J. T., M. Shirai, C. Yokoyama, H. Tsuchimochi, D. O. Schwenke, A. Shimouchi, K. Kangawa and T. Tanabe. (2007). a2-Adrenoreceptor mediated sympathoinhibition of heart rate during acute hypoxia is diminished in conscious prostacyclin synthase deficient mice. Pflugers Archives: European Journal of Physiology 454, 29-39.
10. Schwenke, D. O., J. T. Pearson, K. Umetani, K. Kangawa and M. Shirai. (2007). Imaging of the pulmonary circulation in the closed-chest rat using synchrotron radiation microangiography. Journal of Applied Physiology 102, 787-93.
11. Schwenke, D. O., J. T. Pearson, H. Tsuchimochi, K. Kangawa and M. Shirai. (2007). Pulmonary vascular reactivity of spontaneously hypertensive rats is exacerbated in response to the central administration of exogenous nitric oxide. Clinical and Experimental Pharmacology and Physiology 34, 88-94.
12. Pearson, J.T., M. Shirai, H. Tsuchimochi, D. O. Schwenke, T. Ishida, K. Kangawa, H. Suga and N. Yagi. (2007) Effects of sustained length-dependent activation on in situ cross-bridge dynamics in rat hearts. Biophysics Journal 93, 4319-4329.
13. Schwenke, D. O., J. T. Pearson, K. Kangawa, K. Umetani and M. Shirai. (2008) Changes in macrovessel pulmonary blood flow distribution following pulmonary hypertension - assessed using synchrotron radiation microangiography. Journal of Applied Physiology 104:88-96.
14. Shirai, M., D.O. Schwenke, G.A. Eppel, R.G. Evans, A.J. Edgley, H. Tsuchimochi, K. Umetani, and J. T. Pearson. (2009) Synchrotron based angiography for investigating regulation of vasomotor function in the microcirculation in vivo. Clinical and Experimental Pharmacology and Physiology 36:107-116.
15. Pearson, J.T. and R.A. Lewis. (2009). Introduction to the Frontiers in Research Review: Synchrotron Radiation for Dynamic Imaging of Living Systems. Clinical and Experimental Pharmacology and Physiology 36:84-87.
16. Schwenke, D. O., J. T. Pearson, K. Umetani, M. Shirai and P Cragg. Pulmonary blood flow changes in monocrotaline-induced versus hypoxia induced models of pulmonary hypertension: comparisons using synchrotron radiation. Journal of Hypertension. (accepted Feb 27, 2009)
17. Eppel, G.A., D. Lo Jacono, M. Shirai, K. Umetani, R.G. Evans and J.T. Pearson. (2009). Contrast microangiography of the rat renal microcirculation in vivo using synchrotron radiation. Am J Physiol – Renal  296:F1023-1031.