The aim of this investigation is to identify the receptors which are activated as left ventricular dysfunction (LVD) evolves. It is likely that activation of pulmonary receptors contributes to the symptoms associated with LVD such as wheezing and rapid respiration. Sensory information from the lung is conveyed to the brain by four groups of vagal receptors (1) the slowly adapting receptors (SAR), (2) Rapidly adapting receptors (RAR), (3) Bronchial C and, (4) Pulmonary C fibers. Over the next 5 years, specific hypotheses relating to the following groups of experiments will be tested. I) Effect of acute small changes in Starling forces on sensory receptor subtypes in the lung II) Effect of acute-on-chronic changes in the Starling forces on the activity of pulmonary receptors III) Effect of activating the pulmonary receptors upon renal function IV) Effect of activating the pulmonary receptors upon respiratory rate, tidal volume and airway resistance Pulmonary receptors will be activated by obstructing lymph drainage from the lung. V) Effect of changing Starling forces in the lung on the distribution of interstitial fluid in the lung These experiments will define the nature of the microvascular disturbance created by the stimuli which activate the receptors. VI) Histological studies These studies will identify the distribution of vagal sensory receptors in the tracheobronchial tree. Sensory endings will be identified on the basis of silver staining of myelinated axons, degenerative changes in the nerve endings following cervical vagotomy and the presence of diamines following injections of horse radish peroxidase into the nodose ganglion.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Program Projects (P01)
Project #
5P01HL052165-03
Application #
6242332
Study Section
Project Start
1997-07-01
Project End
1998-06-30
Budget Start
1996-10-01
Budget End
1997-09-30
Support Year
3
Fiscal Year
1997
Total Cost
Indirect Cost
Name
University of California Davis
Department
Type
DUNS #
094878337
City
Davis
State
CA
Country
United States
Zip Code
95618
Hallam, K M; Edirisinghe, I; Balasuriya, U B R et al. (2007) Effects of mitral regurgitation on the reflex diuresis to pulmonary lymphatic obstruction in rabbits. Exp Lung Res 33:259-75
McCormick, K M; Bravo, E M; Kappagoda, C T (2005) Role of adrenergic receptors in the reflex diuresis in rabbits during pulmonary lymphatic obstruction. Exp Physiol 90:341-7
Ma, A A; Ravi, K; Bravo, E M et al. (2004) Effects of gadolinium chloride on slowly adapting and rapidly adapting receptors of the rabbit lung. Respir Physiol Neurobiol 141:125-35
McCormick, K M; Gunawardena, S; Ravi, K et al. (2004) Role of nitric oxide in the reflex diuresis in rabbits during pulmonary lymphatic obstruction. Exp Physiol 89:487-96
Guo, Z-L; Longhurst, J C (2003) Activation of nitric oxide-producing neurons in the brain stem during cardiac sympathoexcitatory reflexes in the cat. Neuroscience 116:167-78
Gunawardena, S; Ravi, K; Longhurst, J C et al. (2002) Responses of C fiber afferents of the rabbit airways and lungs to changes in extra-vascular fluid volume. Respir Physiol Neurobiol 132:239-51
Symons, J D; Gunawardena, S; Kappagoda, C T et al. (2001) Volume overload left ventricular hypertrophy: effects on coronary microvascular reactivity in rabbits. Exp Physiol 86:725-32
Li, P; Tjen-A-Looi, S; Longhurst, J C (2001) Rostral ventrolateral medullary opioid receptor subtypes in the inhibitory effect of electroacupuncture on reflex autonomic response in cats. Auton Neurosci 89:38-47
Liu, Z; Chen, C Y; Bonham, A C (2000) Frequency limits on aortic baroreceptor input to nucleus tractus solitarii. Am J Physiol Heart Circ Physiol 278:H577-85
Daniels, J W; Stebbins, C L; Longhurst, J C (2000) Hemodynamic responses to static and dynamic muscle contractions at equivalent workloads. Am J Physiol Regul Integr Comp Physiol 279:R1849-55

Showing the most recent 10 out of 32 publications