Behaviour of canine pulmonary vagal afferent receptors during sustained acute pulmonary venous pressure elevation.

Kappagoda, C. T.; Man, Godfrey C.W.; Teo, Koon K.

doi:10.1113/jphysiol.1987.sp016869

Cited by 49 publications

(56 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The conduction velocity (Coleridge et al 1965;Paintal, 1973;Coleridge & Coleridge, 1977), base-level activity (Kappagoda et al 1987;Jonzon et al 1988) and mechanical sensitivity (Coleridge et al 1965;Armstrong & Luck, 1974;Kappagoda et al 1987) of C fibres of other species compare similarly with C fibre endings in the rat lung. Rat C fibre endings have a high pressure threshold and adaptation characteristics that are not considered rapidly adapting to mechanical stimuli.…”

Section: Fibresmentioning

confidence: 99%

Identification of vagal sensory receptors in the rat lung: are there subtypes of slowly adapting receptors?

Bergren

Peterson

1993

The Journal of Physiology

View full text Add to dashboard Cite

SUMMARY1. We studied the characteristics of pulmonary sensory receptors whose afferent fibres are in the left vagus nerve of opened-chest rats. The activity of these receptors was recorded during mechanical ventilation approximating eupnoea, as well as during deflation, stepwise inflations and constant-pressure inflations of the lungs. Data were also collected from closed-chest rats and analysed separately.2. Ninety-four per cent of receptors were located in the ipsilateral lung or airways with the remainder in the contralateral lung.3. Not only were slowly adapting receptors (SARs) the most abundant pulmonary receptors but 21 % of them were either exclusively or predominantly active during the deflationary phase of the ventilatory cycle. Deflationary units were found in opened-and closed-chest rats. The average conduction velocity for all fibres innervating SARs averaged 29-7 m s-'. 4. We found rapidly adapting receptors (RARs) to be extremely rare in the rat. Their activity was sparse and irregular. The conduction velocities of fibres innervating RARs averaged 12 3 m s-'.5. Far more abundant than RARs in the remaining population of pulmonary fibres were C fibres. They were observed to have an average conduction velocity of 2-1 m s-1, base-level activity which was irregular and a high pressure threshold of activation and were stimulated by intravenous capsaicin injection.6. Notable differences exist between pulmonary receptors in rats and those reported in other species. The variations include the abundant existence of intrapulmonary SARs with exclusively deflationary modulation and the rarity of RARs. We also encountered C fibres which have not previously been described systematically in the rat.

show abstract

Section: Fibresmentioning

confidence: 99%

Identification of vagal sensory receptors in the rat lung: are there subtypes of slowly adapting receptors?

Bergren

Peterson

1993

The Journal of Physiology

View full text Add to dashboard Cite

show abstract

“…The SARs showed a slow rate of adaptation to the maintained inflation while the RARs adapted rapidly. Additionally, an adaptation index was also calculated as described previously (Kappagoda et al 1987). Receptors with an adaptation index > 70% were accepted as RARs (Widdicombe, 1954;Vidruk et al 1977).…”

Section: Identification Of the Receptorsmentioning

confidence: 99%

“…Recording action potentials and measurement of conduction velocity These procedures have been described in detail previously (Kappagoda et al 1987). Afferent impulses were recorded from slips of the left or right cervical vagus using silver chloride electrodes, the outputs of which were amplified and recorded.…”

Section: Pulmonary Congestion and Vagal Receptorsmentioning

confidence: 99%

“…1P67 mm, Intramedic polyethylene tubing), also inserted into the left atrium through the appendage, was used to measure the left atrial pressure. Cardiovascular pressures, electrocardiogram and action potentials were recorded on light sensitive paper as described previously (Kappagoda et al 1987). The arterial P., and pH of the animals were maintained within physiological limits (see Kappagoda, Linden & Snow, 1970).…”

Section: Generalmentioning

confidence: 99%

“…It is generally accepted that there are four major types of vagal sensory receptors in the airways: the slowly adapting pulmonary stretch receptors (SARs), the rapidly adapting receptors (RARs), the bronchial C fibre receptors and the type JU (pulmonary C fibre) receptors (Sant'Ambrogio, 1982). It has been shown that of these four, the RARs were the most sensitive to pulmonary venous congestion (Kappagoda, Man & Teo, 1987). It was suggested that the RARs were stimulated by fluid fluxes within the pulmonary extravascular space.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Responses of slowly and rapidly adapting receptors in the airways of rabbits to changes in the Starling forces.

Hargreaves

Ravindran

Kappagoda

1991

The Journal of Physiology

Self Cite

View full text Add to dashboard Cite

SUMMARY1. The responses of the rapidly adapting receptors (RARs) and the slowly adapting receptors (SARs) of the airways to changes in the Starling forces regulating fluid exchange in the pulmonary extravascular space were investigated in anaesthetized rabbits. The hydrostatic pressure in the pulmonary microvasculature was raised by partial obstruction of the mitral valve (mean left atrial pressure increased by approximately 5 and 10 mmHg above the control values) and the concentration of plasma proteins was reduced by plasmapheresis (the total plasma protein concentration reduced by 18 %).2. There was a significant correlation between the action potentials generated by RARs and mean left atrial pressure (n = 12). A similar response was not observed in SARs (n = 12).3. After plasmapheresis, there was an increase in the resting activity of the RARs (n = 5). In addition, the stimulus-response curve relating mean left atrial pressure and RAR activity was significantly shifted to the left compared to the one elicited before plasmapheresis. Plasmapheresis failed to influence the activity of SARs (n = 5).4. Obstruction of the pulmonary lymph flow by raising the afterload in the right external jugular vein caused a significant increase in the activity of RARs (n = 6). This response was also maintained during the entire period of lymphatic obstruction.5. The results show that manipulation of the Starling forces within the lung influences the RAR activity profoundly. It is suggested that the stimulus for the RARs may be a function of the fluid fluxes in the pulmonary extravascular space.

show abstract

Sensory Nerves in Lung and Airways

Lee

2014

Comprehensive Physiology

113

157

View full text Add to dashboard Cite

Sensory nerves innervating the lung and airways play an important role in regulating various cardiopulmonary functions and maintaining homeostasis under both healthy and disease conditions. Their activities conducted by both vagal and sympathetic afferents are also responsible for eliciting important defense reflexes that protect the lung and body from potential health-hazardous effects of airborne particulates and chemical irritants. This article reviews the morphology, transduction properties, reflex functions, and respiratory sensations of these receptors, focusing primarily on recent findings derived from using new technologies such as neural immunochemistry, isolated airway-nerve preparation, cultured airway neurons, patch-clamp electrophysiology, transgenic mice, and other cellular and molecular approaches. Studies of the signal transduction of mechanosensitive afferents have revealed a new concept of sensory unit and cellular mechanism of activation, and identified additional types of sensory receptors in the lung. Chemosensitive properties of these lung afferents are further characterized by the expression of specific ligand-gated ion channels on nerve terminals, ganglion origin, and responses to the action of various inflammatory cells, mediators, and cytokines during acute and chronic airway inflammation and injuries. Increasing interest and extensive investigations have been focused on uncovering the mechanisms underlying hypersensitivity of these airway afferents, and their role in the manifestation of various symptoms under pathophysiological conditions. Several important and challenging questions regarding these sensory nerves are discussed. Searching for these answers will be a critical step in developing the translational research and effective treatments of airway diseases.

show abstract

Behaviour of canine pulmonary vagal afferent receptors during sustained acute pulmonary venous pressure elevation.

Abstract: SUMMARY1. The effects of an acute sustained increase in pulmonary venous pressure induced by partial obstruction of the mitral valve on the activity of

Cited by 49 publications

References 25 publications

Identification of vagal sensory receptors in the rat lung: are there subtypes of slowly adapting receptors?

Identification of vagal sensory receptors in the rat lung: are there subtypes of slowly adapting receptors?

Responses of slowly and rapidly adapting receptors in the airways of rabbits to changes in the Starling forces.

Sensory Nerves in Lung and Airways

Contact Info

Product

Resources

About