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Seckler JM, Getsy PM, May WJ, Gaston B, Baby SM, Lewis THJ, Bates JN, Lewis SJ. Hypoxia releases S-nitrosocysteine from carotid body glomus cells-relevance to expression of the hypoxic ventilatory response. Front Pharmacol 2023; 14:1250154. [PMID: 37886129 PMCID: PMC10598756 DOI: 10.3389/fphar.2023.1250154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 09/13/2023] [Indexed: 10/28/2023] Open
Abstract
We have provided indirect pharmacological evidence that hypoxia may trigger release of the S-nitrosothiol, S-nitroso-L-cysteine (L-CSNO), from primary carotid body glomus cells (PGCs) of rats that then activates chemosensory afferents of the carotid sinus nerve to elicit the hypoxic ventilatory response (HVR). The objective of this study was to provide direct evidence, using our capacitive S-nitrosothiol sensor, that L-CSNO is stored and released from PGCs extracted from male Sprague Dawley rat carotid bodies, and thus further pharmacological evidence for the role of S-nitrosothiols in mediating the HVR. Key findings of this study were that 1) lysates of PGCs contained an S-nitrosothiol with physico-chemical properties similar to L-CSNO rather than S-nitroso-L-glutathione (L-GSNO), 2) exposure of PGCs to a hypoxic challenge caused a significant increase in S-nitrosothiol concentrations in the perfusate to levels approaching 100 fM via mechanisms that required extracellular Ca2+, 3) the dose-dependent increases in minute ventilation elicited by arterial injections of L-CSNO and L-GSNO were likely due to activation of small diameter unmyelinated C-fiber carotid body chemoafferents, 4) L-CSNO, but not L-GSNO, responses were markedly reduced in rats receiving continuous infusion (10 μmol/kg/min, IV) of both S-methyl-L-cysteine (L-SMC) and S-ethyl-L-cysteine (L-SEC), 5) ventilatory responses to hypoxic gas challenge (10% O2, 90% N2) were also due to the activation of small diameter unmyelinated C-fiber carotid body chemoafferents, and 6) the HVR was markedly diminished in rats receiving L-SMC plus L-SEC. This data provides evidence that rat PGCs synthesize an S-nitrosothiol with similar properties to L-CSNO that is released in an extracellular Ca2+-dependent manner by hypoxia.
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Affiliation(s)
- James M. Seckler
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
| | - Paulina M. Getsy
- Departments of Pediatrics, Case Western Reserve University, Cleveland, OH, United States
| | - Walter J. May
- Department of Pediatrics, University of Virginia, Charlottesville, Virginia, United States
| | - Benjamin Gaston
- Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, United States
| | | | - Tristan H. J. Lewis
- Departments of Pediatrics, Case Western Reserve University, Cleveland, OH, United States
| | - James N. Bates
- Department of Anesthesia, University of Iowa, Iowa City, IA, United States
| | - Stephen J. Lewis
- Departments of Pediatrics, Case Western Reserve University, Cleveland, OH, United States
- Departments of Pharmacology, Case Western Reserve University, Cleveland, OH, United States
- Functional Electrical Stimulation Center, Case Western Reserve University, Cleveland, OH, United States
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Ventilatory responses during and following hypercapnic gas challenge are impaired in male but not female endothelial NOS knock-out mice. Sci Rep 2021; 11:20557. [PMID: 34663876 PMCID: PMC8523677 DOI: 10.1038/s41598-021-99922-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 09/24/2021] [Indexed: 11/28/2022] Open
Abstract
The roles of endothelial nitric oxide synthase (eNOS) in the ventilatory responses during and after a hypercapnic gas challenge (HCC, 5% CO2, 21% O2, 74% N2) were assessed in freely-moving female and male wild-type (WT) C57BL6 mice and eNOS knock-out (eNOS-/-) mice of C57BL6 background using whole body plethysmography. HCC elicited an array of ventilatory responses that were similar in male and female WT mice, such as increases in breathing frequency (with falls in inspiratory and expiratory times), and increases in tidal volume, minute ventilation, peak inspiratory and expiratory flows, and inspiratory and expiratory drives. eNOS-/- male mice had smaller increases in minute ventilation, peak inspiratory flow and inspiratory drive, and smaller decreases in inspiratory time than WT males. Ventilatory responses in female eNOS-/- mice were similar to those in female WT mice. The ventilatory excitatory phase upon return to room-air was similar in both male and female WT mice. However, the post-HCC increases in frequency of breathing (with decreases in inspiratory times), and increases in tidal volume, minute ventilation, inspiratory drive (i.e., tidal volume/inspiratory time) and expiratory drive (i.e., tidal volume/expiratory time), and peak inspiratory and expiratory flows in male eNOS-/- mice were smaller than in male WT mice. In contrast, the post-HCC responses in female eNOS-/- mice were equal to those of the female WT mice. These findings provide the first evidence that the loss of eNOS affects the ventilatory responses during and after HCC in male C57BL6 mice, whereas female C57BL6 mice can compensate for the loss of eNOS, at least in respect to triggering ventilatory responses to HCC.
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Getsy PM, Sundararajan S, May WJ, von Schill GC, McLaughlin DK, Palmer LA, Lewis SJ. Short-term facilitation of breathing upon cessation of hypoxic challenge is impaired in male but not female endothelial NOS knock-out mice. Sci Rep 2021; 11:18346. [PMID: 34526532 PMCID: PMC8443732 DOI: 10.1038/s41598-021-97322-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 08/09/2021] [Indexed: 02/08/2023] Open
Abstract
Decreases in arterial blood oxygen stimulate increases in minute ventilation via activation of peripheral and central respiratory structures. This study evaluates the role of endothelial nitric oxide synthase (eNOS) in the expression of the ventilatory responses during and following a hypoxic gas challenge (HXC, 10% O2, 90% N2) in freely moving male and female wild-type (WT) C57BL6 and eNOS knock-out (eNOS-/-) mice. Exposure to HXC caused an array of responses (of similar magnitude and duration) in both male and female WT mice such as, rapid increases in frequency of breathing, tidal volume, minute ventilation and peak inspiratory and expiratory flows, that were subject to pronounced roll-off. The responses to HXC in male eNOS-/- mice were similar to male WT mice. In contrast, several of the ventilatory responses in female eNOS-/- mice (e.g., frequency of breathing, and expiratory drive) were greater compared to female WT mice. Upon return to room-air, male and female WT mice showed similar excitatory ventilatory responses (i.e., short-term potentiation phase). These responses were markedly reduced in male eNOS-/- mice, whereas female eNOS-/- mice displayed robust post-HXC responses that were similar to those in female WT mice. Our data demonstrates that eNOS plays important roles in (1) ventilatory responses to HXC in female compared to male C57BL6 mice; and (2) expression of post-HXC responses in male, but not female C57BL6 mice. These data support existing evidence that sex, and the functional roles of specific proteins (e.g., eNOS) have profound influences on ventilatory processes, including the responses to HXC.
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Affiliation(s)
- Paulina M. Getsy
- grid.67105.350000 0001 2164 3847Department of Pediatrics, Biomedical Research Building BRB 319, Case Western Reserve University, 10900 Euclid Avenue Mail Stop 1714, Cleveland, OH 44106-1714 USA ,grid.67105.350000 0001 2164 3847Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH USA
| | - Sripriya Sundararajan
- grid.27755.320000 0000 9136 933XPediatric Respiratory Medicine, University of Virginia School of Medicine, Charlottesville, VA USA ,grid.411024.20000 0001 2175 4264Present Address: Division of Neonatology, Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Walter J. May
- grid.27755.320000 0000 9136 933XPediatric Respiratory Medicine, University of Virginia School of Medicine, Charlottesville, VA USA
| | - Graham C. von Schill
- grid.27755.320000 0000 9136 933XPediatric Respiratory Medicine, University of Virginia School of Medicine, Charlottesville, VA USA
| | - Dylan K. McLaughlin
- grid.27755.320000 0000 9136 933XPediatric Respiratory Medicine, University of Virginia School of Medicine, Charlottesville, VA USA
| | - Lisa A. Palmer
- grid.27755.320000 0000 9136 933XPediatric Respiratory Medicine, University of Virginia School of Medicine, Charlottesville, VA USA
| | - Stephen J. Lewis
- grid.67105.350000 0001 2164 3847Department of Pediatrics, Biomedical Research Building BRB 319, Case Western Reserve University, 10900 Euclid Avenue Mail Stop 1714, Cleveland, OH 44106-1714 USA ,grid.67105.350000 0001 2164 3847Department of Pharmacology, Case Western Reserve University, Cleveland, OH USA ,grid.67105.350000 0001 2164 3847Functional Electrical Stimulation Center, Case Western Reserve University, Cleveland, OH USA
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Lowe M, Park SJ, Nurse CA, Campanucci VA. Purinergic stimulation of carotid body efferent glossopharyngeal neurones increases intracellular Ca2+ and nitric oxide production. Exp Physiol 2013; 98:1199-212. [PMID: 23525247 DOI: 10.1113/expphysiol.2013.072058] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The mammalian carotid body (CB) is a peripheral chemosensory organ that controls ventilation and is innervated by both afferent and efferent nerve fibres. The afferent pathway is stimulated by chemoexcitants, such as hypoxia, hypercapnia and acidosis. The efferent pathway causes inhibition of the sensory discharge via release of NO that originates mainly from neuronal nitric oxide synthase (nNOS)-positive autonomic neurones within the glossopharyngeal nerve (GPN). Recent studies in the rat indicate that these inhibitory GPN neurones and their processes express purinergic P2X receptors and can be activated by ATP, a key excitatory CB neurotransmitter. Here we tested the hypothesis that purinergic agonists stimulate a rise in [Ca(2+)]i, leading to nNOS activation and NO production in isolated GPN neurones, using the fluorescent probes fura-2 and 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate (DAF-FM DA), respectively. ATP caused a dose-dependent increase in [Ca(2+)]i in GPN neurones (EC50 ≈ 1.92 μm) that was markedly inhibited by a combination of 100 μm suramin (a non-specific P2X blocker) and 100 nm Brilliant Blue G (a selective P2X7 blocker). ATP also stimulated NO production in GPN neurones, as revealed by an increase in DAF fluorescence; this NO signal was inhibited by purinergic blockers, chelators of extracellular Ca(2+), the nNOS inhibitor l-NAME and the NO scavenger carboxy-PTIO. The P2X2/3 and P2X7 agonists α,β,-methylene ATP and benzoyl ATP mimicked the effects of ATP. Taken together, these data indicate that ATP may contribute to negative feedback inhibition of CB sensory discharge via purinergic stimulation of NO production in efferent fibres.
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Affiliation(s)
- Michael Lowe
- Department of Biology, McMaster University, Hamilton, Ontario, Canada L8S 4K1
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Modulation of the carotid body sensory discharge by NO: An up-dated hypothesis. Respir Physiol Neurobiol 2012; 184:149-57. [DOI: 10.1016/j.resp.2012.04.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Revised: 04/08/2012] [Accepted: 04/15/2012] [Indexed: 11/23/2022]
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NO modulation of carotid body chemoreception in health and disease. Respir Physiol Neurobiol 2012; 184:158-64. [DOI: 10.1016/j.resp.2012.03.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 03/29/2012] [Accepted: 03/29/2012] [Indexed: 11/18/2022]
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Campanucci VA, Nurse CA. Autonomic innervation of the carotid body: role in efferent inhibition. Respir Physiol Neurobiol 2007; 157:83-92. [PMID: 17353154 DOI: 10.1016/j.resp.2007.01.020] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2006] [Revised: 01/20/2007] [Accepted: 01/22/2007] [Indexed: 10/23/2022]
Abstract
The carotid body (CB) is a chemosensory organ that monitors blood chemicals and initiates compensatory reflex adjustments to maintain homeostasis. The 'afferent' sensory discharge induced by changes in blood chemicals, e.g. low PO(2) (hypoxia), is relayed by carotid sinus nerve (CSN) fibers and has been well studied. Much less is known, however, about a parallel autonomic (parasympathetic) 'efferent' pathway that is the source of CB inhibition. This pathway is the focus of this review which begins with a historical account of the early findings and links them to more recent data on the source of this innervation, and the role of endogenous neurotransmitters in efferent inhibition. We review evidence that these autonomic neurons are embedded in 'paraganglia' within the glossopharyngeal (GPN) and CSN nerves, and for the role of nitric oxide (NO) in mediating efferent inhibition. Finally, we discuss recent data linking the action of hypoxia and a key CB neurotransmitter, i.e. ATP, to potential mechanisms for activating this efferent pathway.
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Campanucci VA, Zhang M, Vollmer C, Nurse CA. Expression of multiple P2X receptors by glossopharyngeal neurons projecting to rat carotid body O2-chemoreceptors: role in nitric oxide-mediated efferent inhibition. J Neurosci 2006; 26:9482-93. [PMID: 16971532 PMCID: PMC6674604 DOI: 10.1523/jneurosci.1672-06.2006] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In mammals, ventilation is peripherally controlled by the carotid body (CB), which receives afferent innervation from the petrosal ganglion and efferent innervation from neurons located along the glossopharyngeal nerve (GPN). GPN neurons give rise to the "efferent inhibitory" pathway via a plexus of neuronal nitric oxide (NO) synthase-positive fibers, believed to be responsible for CB chemoreceptor inhibition via NO release. Although NO is elevated during natural CB stimulation by hypoxia, the underlying mechanisms are unclear. We hypothesized that ATP, released by rat CB chemoreceptors (type 1 cells) and/or red blood cells during hypoxia, may directly activate GPN neurons and contribute to NO-mediated inhibition. Using combined electrophysiological, molecular, and confocal immunofluorescence techniques, we detected the expression of multiple P2X receptors in GPN neurons. These receptors involve at least four different purinergic subunits: P2X2 [and the splice variant P2X2(b)], P2X3, P2X4, and P2X7. Using a novel coculture preparation of CB type I cell clusters and GPN neurons, we tested the role of P2X signaling on CB function. In cocultures, fast application of ATP, or its synthetic analog 2',3'-O-(4 benzoylbenzoyl)-ATP, caused type I cell hyperpolarization that was prevented in the presence of the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide potassium. These data suggest that ATP released during hypoxic stress from CB chemoreceptors (and/or red blood cells) will cause GPN neuron depolarization mediated by multiple P2X receptors. Activation of this pathway will lead to calcium influx and efferent inhibition of CB chemoreceptors via NO synthesis and consequent release.
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Abstract
Peripheral and central chemoreflexes are the dominant autonomic mechanisms regulating ventilatory patterns in response to changes in partial pressures of oxygen and carbon dioxide in arterial blood and exert powerful effects on neural circulatory control. Both reflex pathways are capable of eliciting increases in sympathetic nerve traffic and consequent increases in blood pressure. Chronic heart failure is accompanied by a sustained elevation in sympathetic nerve traffic, which is thought to be an important component in the pathophysiology and progression of the disease. The role of chemoreflex mechanisms in the control of sympathetic function during heart failure is an important topic for which there are many questions and few answers. This review summarizes available evidence documenting peripheral and central chemoreflex function in heart failure, possible mechanisms for their alteration, and their possible contribution to ventilatory, and circulatory abnormalities that occur in heart failure.
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Affiliation(s)
- H D Schultz
- Department of Physiology and Biophysics, University of Nebraska College of Medicine, 984575 Nebraska Medical Center, Omaha, NE 68198-4575, USA.
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Campanucci VA, Nurse CA. Biophysical characterization of whole-cell currents in O2-sensitive neurons from the rat glossopharyngeal nerve. Neuroscience 2005; 132:437-51. [PMID: 15802195 DOI: 10.1016/j.neuroscience.2004.11.058] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/24/2004] [Indexed: 11/18/2022]
Abstract
In this study we use nystatin perforated-patch and conventional whole-cell recording to characterize the biophysical properties of neuronal nitric oxide synthase (nNOS)-expressing paraganglion neurons from the rat glossopharyngeal nerve (GPN), that are thought to provide NO-mediated efferent inhibition of carotid body chemoreceptors. These GPN neurons occur in two populations, a proximal one near the bifurcation of the GPN and the carotid sinus nerve, and a more distal one located further along the GPN. Both populations were visualized in whole mounts by vital staining with the styryl pyridinium dye, 4-Di-2-ASP (D289). Following isolation in vitro, proximal and distal neurons had similar input resistances (mean: 1.5 and 1.6 GOmega, respectively), input capacitances (mean: 25.0 and 27.4 pF, respectively), and resting potentials (mean: -53.9 and -53.3 mV, respectively). All neurons had similar voltage-dependent currents composed of: tetrodotoxin (TTX)-sensitive Na+ currents (IC50 approximately 0.2 microM), prolonged and transient Ca2+ currents, and delayed rectifier-type K+ currents. Threshold activation for the Na+ currents was approximately -30 mV and they were inactivated within 10 ms. Inward Ca2+ currents consisted of nifedipine-sensitive L-type, omega-agatoxin IVA-sensitive P/Q-type, omega-conotoxin GVIA-sensitive N-type, SNX-482-sensitive R-type, and Ni2+-sensitive, but SNX-482-insensitive, T-type channels. The voltage-dependent outward K+ currents were sensitive to tetraethylammonium (TEA; 10 mM) and 4-aminopyridine (4-AP; 2 mM). Exposure to a chemosensory stimulus, hypoxia (PO2 range: 80-5 Torr), caused a dose-dependent decrease in K+ current which persisted in the presence of TEA and 4-AP, consistent with the involvement of background K+ channels. Under current clamp, GPN neurons generated TTX-sensitive action potentials, and in spontaneously active neurons, hypoxia caused membrane depolarization and an increase in firing frequency. These properties endow GPN neurons with an exquisite ability to regulate carotid body chemoreceptor function during hypoxia, via voltage-gated Ca2+-entry, activation of nNOS, and release of NO.
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Affiliation(s)
- V A Campanucci
- Department of Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4K1
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Campanucci VA, Fearon IM, Nurse CA. A novel O2-sensing mechanism in rat glossopharyngeal neurones mediated by a halothane-inhibitable background K+ conductance. J Physiol 2003; 548:731-43. [PMID: 12640017 PMCID: PMC2342899 DOI: 10.1113/jphysiol.2002.035998] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Modulation of K+ channels by hypoxia is a common O2-sensing mechanism in specialised cells. More recently, acid-sensitive TASK-like background K+ channels, which play a key role in setting the resting membrane potential, have been implicated in O2-sensing in certain cell types. Here, we report a novel O2 sensitivity mediated by a weakly pH-sensitive background K+ conductance in nitric oxide synthase (NOS)-positive neurones of the glossopharyngeal nerve (GPN). This conductance was insensitive to 30 mM TEA, 5 mM 4-aminopyridine (4-AP) and 200 microM Cd2+, but was reversibly inhibited by hypoxia (O2 tension (PO2) = 15 mmHg), 2-5 mM halothane, 10 mM barium and 1 mM quinidine. Notably, the presence of halothane occluded the inhibitory effect of hypoxia. Under current clamp, these agents depolarised GPN neurones. In contrast, arachidonic acid (5-10 microM) caused membrane hyperpolarisation and potentiation of the background K+ current. This pharmacological profile suggests the O2-sensitive conductance in GPN neurones is mediated by a class of background K+ channels different from the TASK family; it appears more closely related to the THIK (tandem pore domain halothane-inhibited K+) subfamily, or may represent a new member of the background K+ family. Since GPN neurones are thought to provide NO-mediated efferent inhibition of the carotid body (CB), these channels may contribute to the regulation of breathing during hypoxia via negative feedback control of CB function, as well as to the inhibitory effect of volatile anaesthetics (e.g. halothane) on respiration.
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Affiliation(s)
- Verónica A Campanucci
- Department of Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4K1
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Valdés V, Mosqueira M, Rey S, Del Rio R, Iturriaga R. Inhibitory effects of NO on carotid body: contribution of neural and endothelial nitric oxide synthase isoforms. Am J Physiol Lung Cell Mol Physiol 2003; 284:L57-68. [PMID: 12388352 DOI: 10.1152/ajplung.00494.2001] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We tested the hypothesis that nitric oxide (NO) produced within the carotid body is a tonic inhibitor of chemoreception and determined the contribution of neuronal and endothelial nitric oxide synthase (eNOS) isoforms to the inhibitory NO effect. Accordingly, we studied the effect of NO generated from S-nitroso-N-acetylpenicillamide (SNAP) and compared the effects of the nonselective inhibitor N(omega)-nitro-l-arginine methyl ester (l-NAME) and the selective nNOS inhibitor 1-(2-trifluoromethylphenyl)-imidazole (TRIM) on chemosensory dose-response curves induced by nicotine and NaCN and responses to hypoxia (Po(2) approximately 30 Torr). CBs excised from pentobarbitone-anesthetized cats were perfused in vitro with Tyrode at 38 degrees C and pH 7.40, and chemosensory discharges were recorded from the carotid sinus nerve. SNAP (100 microM) reduced the responses to nicotine and NaCN. l-NAME (1 mM) enhanced the responses to nicotine and NaCN by increasing their duration, but TRIM (100 microM) only enhanced the responses to high doses of NaCN. The amplitude of the response to hypoxia was enhanced by l-NAME but not by TRIM. Our results suggest that both isoforms contribute to the NO action, but eNOS being the main source for NO in the cat CB and exerting a tonic effect upon chemoreceptor activity.
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Affiliation(s)
- Viviana Valdés
- Laboratorio de Neurobiologia, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago 1, Chile
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Ichikawa H. Innervation of the carotid body: Immunohistochemical, denervation, and retrograde tracing studies. Microsc Res Tech 2002; 59:188-95. [PMID: 12384963 DOI: 10.1002/jemt.10193] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This review presents information about multiple neurochemical substances in the carotid body. Nerve fibers around blood vessels and glomus cells within the chemoreceptive organ contain immunoreactivities (IR) for tyrosine hydroxylase (TH), calcitonin gene-related peptide (CGRP), substance P (SP), galanin (GAL), vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), calretinin (CR), calbindin D-28k (CB), parvalbumin (PV), and nitric oxide synthase (NOS). Parasympathetic neurons scattered around the carotid body contain VIP, choline acetyltransferase, and vanilloid receptor 1-like receptor. In the mammalian carotid body, transection of the carotid sinus nerve (CSN) causes the absence or decrease of CGRP-, SP-, and NOS-immunoreactive (IR) nerve fibers, whereas all NPY-IR nerve fibers disappear after removal of the superior cervical ganglion. Most VIP-IR nerve fibers disappear but a few persist after sympathetic ganglionectomy. In addition, the CSN transection appears to cause the acquisition of GAL-IR in originally immunonegative glomus cells and nerve fibers within the rat carotid body. On the other hand, 4%, 25%, 17%, and less than 1% of petrosal neurons retrogradely labeled from the rat CSN contain TH-, CGRP-, SP-, and VIP-IR, respectively. In the chicken carotid body, many CGRP- and SP-IR nerve fibers disappear after vagus nerve transection or nodose ganglionectomy. GAL-, NPY-, and VIP-IR nerve fibers mostly disappear after removal of the 14th cervical ganglion of the sympathetic trunk. The origin and functional significance of the various neurochemical substances present in the carotid body is discussed.
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Affiliation(s)
- Hiroyuki Ichikawa
- Department of Oral Function and Anatomy, Okayama University, Graduate School of Medicine and Dentistry, Okayama 700, Japan.
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Mosqueira M, Iturriaga R. Carotid body chemosensory excitation induced by nitric oxide: involvement of oxidative metabolism. Respir Physiol Neurobiol 2002; 131:175-87. [PMID: 12126919 DOI: 10.1016/s1569-9048(02)00020-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Nitric oxide (NO) produces a dual effect on carotid body (CB) oxygen chemoreception. At low concentration, NO inhibits chemosensory response to hypoxia, while in normoxia, medium and high [NO] increases the frequency of carotid chemosensory discharges (f(x)). Since NO and peroxynitrite inhibit mitochondrial respiration, it is plausible that the NO-induced excitation may depend on the mitochondrial oxidative metabolism. To test this hypothesis, we studied the effects of oligomycin, FCCP and antimycin A that produce selective blockade of hypoxic and NaCN-induced chemosensory responses, leaving nicotinic response less affected. CBs excised from pentobarbitone-anaesthetised cats were perfused in vitro with Tyrode (P(O(2)) approximately 125 Torr, pH 7.40 at 38 degrees C). Hypoxia (P(O(2)) approximately equal 30 Torr), NaCN and nicotine (1-100 microg) and S-nitroso-N-acetylpenicillamide (SNAP, 300-600 microg) increased f(x). Oligomycin (12.5-25 microg), antimycin A (10 microg) and FCCP (5 microM) transiently increased f(x). Subsequently, chemosensory responses to hypoxia, NaCN and SNAP were reduced or abolished, while the response to nicotine was less affected. The electron donor system tetramethyl-p-phenylene diamide and ascorbate that bypasses the electron chain blockade produced by antimycin A, restores the excitatory responses to NaCN and SNAP. Present results suggest that the chemoexcitatory effect of NO depends on the integrity of mitochondrial metabolism.
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Affiliation(s)
- Matias Mosqueira
- Laboratorio de Neurobiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 1, 114-D, Santiago, Chile
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Iturriaga R, Mosqueira M. The excitatory effect of nitric oxide on carotid body chemoreception is blocked by oligomycin. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2002; 499:55-60. [PMID: 11729934 DOI: 10.1007/978-1-4615-1375-9_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Affiliation(s)
- R Iturriaga
- Laboratorio de Neurobiologia, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago
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Talman WT, Dragon DN, Ohta H, Lin LH. Nitroxidergic influences on cardiovascular control by NTS: a link with glutamate. Ann N Y Acad Sci 2001; 940:169-78. [PMID: 11458675 DOI: 10.1111/j.1749-6632.2001.tb03675.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Glutamate (GLU) receptor activation, which is important in cardiovascular reflex transmission through the nucleus tractus solitarii (NTS), leads to release of nitric oxide (NO.) from central nitroxidergic neurons. Therefore, we hypothesized that GLU and NO. are linked in cardiovascular control by NTS. We first sought to determine if NO. released into NTS led to cardiovascular changes like those produced by GLU and found that the nitrosothiol S-nitrosocysteine, but not NO. itself or other NO. donors, elicited such responses in anesthetized rats. The responses were dependent on activation of soluble guanylate cyclase but, not being affected by a scavenger of NO., likely did not depend on release of NO. into the extracellular space. Responses to ionotropic GLU agonists in NTS, like those to S-nitrosocysteine, were inhibited by inhibition of soluble guanylate cyclase. Inhibition of neuronal NO. synthase (nNOS) also inhibited responses to ionotropic GLU agonists. The apparent physiologic link between GLU and NO. mechanisms in NTS was further supported by anatomical studies that demonstrated frequent association between GLU-containing nerve terminals and neurons containing nNOS. Furthermore, GLU receptors were often found on NTS neurons that were immunoreactive for nNOS. The anatomical relationships between GLU and nNOS and GLU receptors and nNOS were more pronounced in some subnuclei of NTS than in others. While seen in subnuclei that are known to receive cardiovascular afferents, the association was even more prominent in subnuclei that receive gastrointestinal afferents. These studies support a role for nitroxidergic neurons in mediating cardiovascular and other visceral reflex responses that result from release of GLU into the NTS.
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Affiliation(s)
- W T Talman
- Laboratory of Neurobiology, Department of Neurology and Neuroscience Program, University of Iowa, Department of Veterans Affairs Medical Center, Iowa City, Iowa 52242, USA.
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Iturriaga R, Villanueva S, Alcayaga J. Nitric oxide modulation of carotid chemoreception. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2000; 475:761-8. [PMID: 10849718 DOI: 10.1007/0-306-46825-5_76] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Affiliation(s)
- R Iturriaga
- Laboratories of Neurobiology, Faculty of Biological Sciences, P. Catholic University of Chile, Santiago, Chile
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Iturriaga R, Villanueva S, Mosqueira M. Dual effects of nitric oxide on cat carotid body chemoreception. J Appl Physiol (1985) 2000; 89:1005-12. [PMID: 10956344 DOI: 10.1152/jappl.2000.89.3.1005] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We studied the effects of nitric oxide (NO) released by NO donors on cat carotid body (CB) chemosensory activity during normoxia and hypoxia. CBs excised from pentobarbital sodium-anaesthetized cats were perfused with Tyrode at 38 degrees C and pH 7.40. The frequency of chemosensory discharges (f(x)) was recorded from the carotid sinus nerve, and changes of NO concentration were measured by a chronoamperometric technique, with NO-selective carbon-fiber microelectrodes inserted in the CB. During steady chemosensory excitation induced by hypoxia, bolus injections of NO (DeltaNO = 0. 5-12 microM), released by S-nitroso-N-acetylpenicillamine (SNAP) and 6-(2-hydroxy-1-methyl-nitrosohydrazino)-N-methyl-1-hexanamine++ + (NOC-9), transiently reduced f(x) in a dose-dependent manner. However, during normoxia, the same concentration of NO (DeltaNO = 0. 5-13 microM) released by the NO donors increased f(x) in a dose-dependent manner. The present results show a dual effect of NO on CB chemoreception that is dependent on the PO(2) levels. During hypoxia, NO is predominantly an inhibitor of chemoreception, whereas, in normoxia, NO increased f(x). The mechanisms by which NO produces chemosensory excitation during normoxia remain to be determined.
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Affiliation(s)
- R Iturriaga
- Laboratorio de Neurobiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 1, Chile.
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Iturriaga R, Mosqueira M, Villanueva S. Effects of nitric oxide gas on cat carotid body chemosensory response to hypoxia. Brain Res 2000; 855:282-6. [PMID: 10677601 DOI: 10.1016/s0006-8993(99)02369-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
It has been proposed that nitric oxide (NO) is an inhibitory modulator of carotid body (CB) chemoreception to hypoxia. However, the effects of NO gas on carotid chemoreception have not been tested yet. The role played by NO has been revealed by the use of pharmacological tools (i.e., NO donors and NO synthase inhibitors). Here, we studied the effects of NO gas (25 ppm in N(2)) on the chemosensory response to hypoxia (PO(2) approximately 30 Torr) in the cat CB perfused in vitro. During steady hypoxic chemoreceptor excitation, bolus injections or perfusion of Tyrode equilibrated with NO reduced the increased frequency of carotid chemosensory discharges (f(x)). Perfusion for 2 min of Tyrode equilibrated with NO also reduced the rate of the rise of the chemosensory response, as well as the maximal amplitude, as compared with the normal chemosensory response to hypoxia. Present results provide direct evidence that NO gas is an inhibitory modulator of CB hypoxic chemoreception.
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Affiliation(s)
- R Iturriaga
- Laboratory of Neurobiology, Faculty of Biological Sciences, P. Catholic University of Chile, Casilla 114-D, Santiago, Chile.
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20
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Iturriaga R, Alcayaga J, Rey S. Sodium nitroprusside blocks the cat carotid chemosensory inhibition induced by dopamine, but not that by hyperoxia. Brain Res 1998; 799:26-34. [PMID: 9666065 DOI: 10.1016/s0006-8993(98)00456-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We studied the effects of the nitric oxide (NO) synthase inhibitor, Nomega-nitro-L-arginine methyl ester (L-NAME), and the NO donor, sodium nitroprusside (SNP) on cat chemosensory responses to intravenous injections of NaCN (0.1-100 microg/kg) and dopamine (0. 1-20 microg/kg), and to hyperoxic ventilation (100% O2, 60-120 s). Cats were anesthetized with sodium pentobarbitone, paralyzed and artificially ventilated to prevent secondary ventilatory effects. The frequency of chemosensory discharges (fx) was recorded from one sectioned carotid sinus nerve. L-NAME (50 mg/kg i.v.) increased basal fx and slightly potentiated the responses to NaCN and dopamine. SNP (1-2 mg/kg i.v.) increased basal fx, but reduced the NaCN-induced increases of fx over baseline and the transient fx inhibitions induced by dopamine, but not those produced by hyperoxia. Present results indicate that besides the known inhibitory effect of NO on chemosensory responses to low PO2, NO also blocks the chemosensory response to dopamine, leaving hyperoxic responses largely unchanged.
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Affiliation(s)
- R Iturriaga
- Laboratory of Neurobiology, Faculty of Biological Sciences, P. Catholic University of Chile, Casilla 114-D, Santiago 1, Chile.
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Alcayaga J, Iturriaga R, Ramirez J, Readi R, Quezada C, Salinas P. Cat carotid body chemosensory responses to non-hypoxic stimuli are inhibited by sodium nitroprusside in situ and in vitro. Brain Res 1997; 767:384-7. [PMID: 9367274 DOI: 10.1016/s0006-8993(97)00805-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We studied the effects of sodium nitroprusside, a nitric oxide donor, on the chemosensory responses to cyanide and nicotine in the cat carotid body. In situ, sodium nitroprusside infusion reduced the cyanide-evoked responses in a dose-dependent manner. In vitro, Tyrode containing nitroprusside reversibly reduced the cyanide- (by 59%) and nicotine-induced (by 45%) chemosensory responses. The present results suggest that chemosensory responses induced by cyanide and nicotine are reduced by increased nitric oxide content, similarly to the hypoxic chemosensory responses.
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Affiliation(s)
- J Alcayaga
- Laboratorio de Neurobiología, Facultad de Ciencias, Universidad de Chile, Santiago.
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Lahiri S. Peripheral Chemoreceptors and Their Sensory Neurons in Chronic States of Hypo‐ and Hyperoxygenation. Compr Physiol 1996. [DOI: 10.1002/cphy.cp040251] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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He L, Chen J, Dinger B, Stensaas L, Fidone S. Endothelin modulates chemoreceptor cell function in mammalian carotid body. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1996; 410:305-11. [PMID: 9030316 DOI: 10.1007/978-1-4615-5891-0_46] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- L He
- Department of Physiology, University of Utah School of Medicine, Salt Lake City 84108, USA
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