Home > Program Faculty >Marlowe Eldridge Laboratory
The major focus of the Eldridge Laboratory involves integrative cardiopulmonary physiology and pathophysiology as it occurs in isolated heart lung preparations, non-anaesthetized animals and humans, with specific applications to the effects of exercise, acute hypoxia, altitude, and environmental exposure (particulates, endotoxin and ozone). Currently, our specific research activities emphasize the following:
Structural and functional characterization of inducible intrapulmonary arteriovenous pathways in isolated perfused heart lung preparations, non-anaesthetized animals, and healthy humans.
We are investigating the effects of pulmonary vascular pressures and flows on trans-pulmonary passage of various sized fluorescent-labeled polymer (confocal microscopy) and soda lime glass microspheres (micro-CT angiography) in isolated perfused and ventilated rat & dog lungs . We are using contrast echocardiography to determine the prevalence and exercise-intensity dependence of intrapulmonary arteriovenous shunts in a large number of healthy male and female subjects with varying levels of VO 2max and A-aDO 2. We are also attempting to quantify the shunt fraction through the intrapulmonary arteriovenous channels at rest and with exercise in healthy humans using whole body 99m Tc-labeled albumin macroaggregates (MAA) nuclear medicine scanning. We are conducting similar studies in non-anaesthetized animals using neutron-activated, fluorescent-labeled polymer and soda lime glass microspheres of various size ranges.
Influence of hypoxia, hyperoxia, nitric oxide and vasoactive agents on the functional and structural regulation of intrapulmonary arteriovenous pathways in isolated perfused heart lung preparations, non-anaesthetized animals, and healthy humans .
Using the same methods (i.e. contrast echocardiography, 99m Tc-MAA nuclear medicine scanning and neutron-activated, fluorescent-labeled polymer (confocal microscopy), and soda lime glass (micro-CT angiography) microspheres described above, we are investigating the influence of hypoxia, hyperoxia, nitric oxide and vasoactive agentson the functional and structural regulation of these intrapulmonary arteriovenous pathways.
Influence of airway inflammation on pulmonary gas exchange during exercise in healthy and asthmatic humans.
We are investigating the pulmonary gas exchange and mechanics of breathing response to submaximal, pro-longed high-intensity, and maximal aerobic exercise in habitually active individuals with bronchial asthma with and without inhaled steroid therapy. The goal is to determine the influence of lung inflammation on exercise-induced arterial hypoxemia. We are also interested in the influence of ozone exposure on airway inflammation, lung mechanics and gas exchange during exercise in health and disease.
Mechanism of high altitude pulmonary edema (HAPE), with a specific interest HAPE-susceptibility, influence of exercise and growth factors.
We are investigating the combined effects of altitude exposure and exercise on pulmonary capillary integrity in healthy and HAPE-prone subjects. We are also interested in the potential mechanistic role of growth factors (specifically, VEGF and collagen V) in HAPE.
Lung heath and indoor air pollution in high altitude natives.
We are characterizing and quantifying the indoor air exposures during open pit combustion of biomass (wood and dung) in the tents and homes of high altitude natives of the Ladaki, Zanskar and Himalayan mountains. We are relating these exposures to lung function and airway inflammation.
- Lovering AT, Romer LM, Haverkamp HC, Pegelow D, Hokanson JS, Eldridge MW. Intrapulmonary shunting and pulmonary gas exchange during normoxic and hypoxic exercise in healthy humans. J Applied Physiol 104: 2008 (in press).
- Dempsey JA, McKenze D, Haverkamp HC, Eldridge MW. Update in the Understanding of Respiratory Limitations to Exercise Performance in Fit, Active Adults. Chest in press February 2008.
- Stickland MK, Lovering AT, Eldridge MW. Exercise-induced arteriovenous intra-pulmonary shunting in Dogs. Am J Resp Critical Care Med. 176:300-305, 2007
- Haverkamp HC, Dempsey JA, Pegelow DF, Miller JD, Romer LM, Santana M, Eldridge MW. Treatment of airway inflammation improves pulmonary gas exchange during exercise in asthmatic subjects. J Clin Allergy and Immunology 120:39-47, 2007.
- Ghorishi Z, Milstein JM, Poulain FR, Moon-Grady A, Tacy T, Bennett SH, Fineman JR, Eldridge MW. A shear stress paradigm for fractal arterial network remodeling in perinatal lambs with pulmonary hypertension and increased pulmonary blood flow. Am J Physiol: Heart and Circulation 292: H3006-H3018, 2007.
- Lovering AT, Stickland M, Kelso A, Eldridge MW. Direct demonstration of 25- and 50 m m arteriovenous pathways in healthy human and baboon lungs. Am J Physiol: Heart and Circulation: 292:H1777-H1781, 2007.
- Lovering A.T Haverkamp, HC, Romer LM, Hokanson JS, Eldridge MW. Gas exchange impairment in a subject with a history of bronchopulmonary dysplasia (BPD) and high altitude pulmonary edema (HAPE). High Altitude Medicine and Biology 8: 62-67, 2007.
- Eldridge MW, Yoneda, KY, Braun RK, Walby, WF. Effects of altitude and exercise on pulmonary capillary integrity: Evidence for sub-clinical high altitude pulmonary edema. J Applied Physiol. 100: 972-980, 2006.
- Amann M, Eldridge MW, Lovering AT, Pegelow, DF, Stickland M, Dempsey, JA. Arterial oxygen content influences central motor output exercise performance via effects on peripheral locomotor muscle fatigue. J Physiol 575: 937-952, 2006.
- Lovering AT, Stickland Mk, Eldridge MW. Intrapulmonary shunting during normoxic and hypoxic exercise in healthy humans. Adv Exp Med Biol. 588: 31-45, 2006.
- Romer LM, Dempsey JA, Lovering AT, Eldridge MW. Exercise-induced arterial hypoxemia: Consequences for locomotor muscle fatigue. Adv Exp Med Biol. 588: 47-56, 2006.
- Lovering AT, Stickland M, Eldridge MW. Contrast Ultrasound Techniques in the Detection and Quantification of Patent Foramen Ovale: Myth Versus Reality - A Clarification. Stroke 36:1109, 2005
- Lovering, AT, Haverkamp HC, Eldridge MW. The Lung in Extreme Environments: Responses and Limitations of the Respiratory System to Exercise. Clin Chest Med 26 (3):439-457, 2005.
- Haverkamp HC, Dempsey JA, Miller JD, Romer LM, Pegelow DF, Eldridge MW. Repeat exercise normalizes the gas exchange impairment induced by a previous exercise bout in asthmatics . J Applied Physiol. 99: 1843-1852, 2005.
- Haverkamp HC, Dempsey JA, Miller JD, Romer LM, Pegelow DF, Eldridge MW. Gas exchange during exercise in habitually active asthmatics. J Applied Physiol. 99:1938-1950, 2005.
- Mansoor JK, Morrissey BM, Walby WF, Yoneda KY, Juarez M, Kajekar R, Severinghaus JW, Eldridge MW, Schelegle ES. Effect of L-arginine supplementation on breath condensate VEGF, exhaled NO, plasma erythropoietin, and subjective symptoms 4342 M. High Alt Med Biol. 6: 289-300, 2005.
- Rosati JA, Yoneda KY, Yasmeen S, Wood SC, Eldridge MW. Lung health and indoor air pollution in Ladahki highlanders. Archives of Environmental and Occupational Health 60:96-105, 2005.
- Eldridge MW , Dempsey JA, Haverkamp HC, Lovering AT, Hokanson JS. Exercise-induced intrapulmonary arteriovenous shunting in healthy humans. J Applied Physiol. 97:797-805, 2004
Active Grants
Oxygen regulation of intrapulmonary shunts in Hepatopulmonary Syndrome.
Principal Investigators: Nissa Erickson, M.D. and Marlowe Eldridge, M.D.
Agency: UW-ICTR Type 1 Translational Research Pilot Grant
Status: Funded 07/01/2008-06/30/2009 ($41,000)
The major goal of the project is to investigate the functional regulation of intrapulmonary shunts in patients with Hepatopulmonary Syndrome and in an animal model of the disease (common bile duct ligation rat model).
Decompression Risk Minimization in Submarine Escape and Rescue.
Principal Investigator: Marlowe Eldridge M.D.
Agency: DOD Navy # N61331-06-C-0036 (144PW42)
Status: Funded 07/28/2006 – 07/27/2009 ($917,889)
The major goal of this project is to study strategies to minimize decompression illness following rapid ascents from deep dives (i.e., disabled submarines).
Improving Risk Estimation, Safety and Cost-effectiveness in Scuba Diving. Principal Investigator: Marlowe Eldridge M.D.
Agency: COMM NOAA # A06OAR417001 (144PD98)
Status: Funded 03/01/2006 – 01/31/2008 ($268,177)
The major goal of this project is to improve risk estimation and improve strategies to minimize decompression illness in recreational and occupational scuba drivers.
Respiratory Neurobiolgy Training Program
PI: Gordon Mitchell Ph.D.
Agency: National Heart, Lung, and Blood Institute
Type: T32 (HL07654-16, Years 18-20) Period: July 1 2008-June 30 2013;
The major goal of this project is to train pre- and postdoctoral scientists for scientific careers in basic and applied biomedical research and teaching. This grant supports 4 pre-doctorate and 4 post-doctorate trainees per year and is shared with several faculty at UW-Madison. Dr. Eldridge is a Primary Trainer and has mentoring 1 post-doctorate trainee and 1 pre-doctorate trainee using this mechanism.
Grants Pending or in Preparation:
Neurological Decompression Injury: Is Deep Stop Decompression Protective?
Principal Investigator: Marlowe Eldridge M.D.
Agency: DOD Navy
Status: Pending 10/01/2008-09/31/2011 (~$1,300,000)
This major goal ofthese studies is to improve our understanding of neurological decompression sickness and help evaluate deep stop use as a protective decompression strategy. We will use our established sheep model of the diver to determine the effects of various decompression scenarios with and without a deep stop on neurological decompression sickness. A variety of MR imaging techniques, will be used evaluate for subtle neurological injury and more importantly to gain insight into the mechanisms that may contribute to decompression neuronal injury.