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Masliukov PM, Emanuilov AI, Budnik AF. Sympathetic innervation of the development, maturity, and aging of the gastrointestinal tract. Anat Rec (Hoboken) 2023; 306:2249-2263. [PMID: 35762574 DOI: 10.1002/ar.25015] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 04/21/2022] [Accepted: 05/24/2022] [Indexed: 11/10/2022]
Abstract
The sympathetic nervous system inhibits gut motility, secretion, and blood flow in the gut microvasculature and can modulate gastrointestinal inflammation. Sympathetic neurons signal via catecholamines, neuropeptides, and gas mediators. In the current review, we summarize the current understanding of the mature sympathetic innervation of the gastrointestinal tract with a focus mainly on the prevertebral sympathetic ganglia as the main output to the gut. We also highlight recent work regarding the developmental processes of sympathetic innervation. The anatomy, neurochemistry, and connections of the sympathetic prevertebral ganglia with different parts of the gut are considered in adult organisms during prenatal and postnatal development and aging. The processes and mechanisms that control the development of sympathetic neurons, including their migratory pathways, neuronal differentiation, and aging, are reviewed.
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Affiliation(s)
- Petr M Masliukov
- Department of Normal Physiology, Yaroslavl State Medical University, Yaroslavl, Russia
| | - Andrey I Emanuilov
- Department of Human Anatomy, Yaroslavl State Medical University, Yaroslavl, Russia
| | - Antonina F Budnik
- Department of Normal and Pathological Anatomy, Kabardino-Balkarian State University named after H.M. Berbekov, Nalchik, Russia
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The diversity of neuronal phenotypes in rodent and human autonomic ganglia. Cell Tissue Res 2020; 382:201-231. [PMID: 32930881 PMCID: PMC7584561 DOI: 10.1007/s00441-020-03279-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 08/10/2020] [Indexed: 12/29/2022]
Abstract
Selective sympathetic and parasympathetic pathways that act on target organs represent the terminal actors in the neurobiology of homeostasis and often become compromised during a range of neurodegenerative and traumatic disorders. Here, we delineate several neurotransmitter and neuromodulator phenotypes found in diverse parasympathetic and sympathetic ganglia in humans and rodent species. The comparative approach reveals evolutionarily conserved and non-conserved phenotypic marker constellations. A developmental analysis examining the acquisition of selected neurotransmitter properties has provided a detailed, but still incomplete, understanding of the origins of a set of noradrenergic and cholinergic sympathetic neuron populations, found in the cervical and trunk region. A corresponding analysis examining cholinergic and nitrergic parasympathetic neurons in the head, and a range of pelvic neuron populations, with noradrenergic, cholinergic, nitrergic, and mixed transmitter phenotypes, remains open. Of particular interest are the molecular mechanisms and nuclear processes that are responsible for the correlated expression of the various genes required to achieve the noradrenergic phenotype, the segregation of cholinergic locus gene expression, and the regulation of genes that are necessary to generate a nitrergic phenotype. Unraveling the neuron population-specific expression of adhesion molecules, which are involved in axonal outgrowth, pathway selection, and synaptic organization, will advance the study of target-selective autonomic pathway generation.
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Chen BN, Sharrad DF, Hibberd TJ, Zagorodnyuk VP, Costa M, Brookes SJ. Neurochemical characterization of extrinsic nerves in myenteric ganglia of the guinea pig distal colon. J Comp Neurol 2014; 523:742-56. [DOI: 10.1002/cne.23704] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 10/24/2014] [Accepted: 10/29/2014] [Indexed: 12/18/2022]
Affiliation(s)
- Bao Nan Chen
- Department of Human Physiology and Centre for Neuroscience; Flinders Medical Science and Technology, School of Medicine, Flinders University; Bedford Park South Australia Australia
| | - Dale F. Sharrad
- Department of Human Physiology and Centre for Neuroscience; Flinders Medical Science and Technology, School of Medicine, Flinders University; Bedford Park South Australia Australia
| | - Timothy J. Hibberd
- Department of Human Physiology and Centre for Neuroscience; Flinders Medical Science and Technology, School of Medicine, Flinders University; Bedford Park South Australia Australia
| | - Vladimir P. Zagorodnyuk
- Department of Human Physiology and Centre for Neuroscience; Flinders Medical Science and Technology, School of Medicine, Flinders University; Bedford Park South Australia Australia
| | - Marcello Costa
- Department of Human Physiology and Centre for Neuroscience; Flinders Medical Science and Technology, School of Medicine, Flinders University; Bedford Park South Australia Australia
| | - Simon J.H. Brookes
- Department of Human Physiology and Centre for Neuroscience; Flinders Medical Science and Technology, School of Medicine, Flinders University; Bedford Park South Australia Australia
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Wojtkiewicz J, Równiak M, Gonkowski S, Crayton R, Majewski M, Robak A, Białkowska J, Barczewska M. Proliferative enteropathy (PE)-induced changes in the calbindin-immunoreactive (CB-IR) neurons of inferior mesenteric ganglion supplying the descending colon in the pig. J Mol Neurosci 2012; 48:757-65. [PMID: 22170039 PMCID: PMC3447145 DOI: 10.1007/s12031-011-9691-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Accepted: 12/02/2011] [Indexed: 02/06/2023]
Abstract
A subpopulation of the pig inferior mesenteric ganglia (IMG) neurons projecting to the colon exhibit calbindin-like immunoreactivity. It is not known if there are any changes in the chemical coding patterns of these neurons during porcine proliferative enteropathy (PE). To answer this question, juvenile Large White Polish pigs with clinically diagnosed Lawsonia intracellularis infection (PE; n = 3) and a group of uninfected controls (C; n = 3) were compared. The retrograde tracer fast blue (FB) was injected into the descending colons of all animals and then tissue comprising IMGs from both groups was processed for double-labeling immunofluorescence with calbindin-D28k (CB) in combination with either tyrosine hydroxylase (TH), neuropeptide Y (NPY), somatostatin (SOM), vasoactive intestinal polypeptide (VIP), nitric oxide synthase, Leu-enkephalin, substance P, vesicular acetylcholine transporter, galanin, or pituitary adenylate cyclase-activating polypeptide. Immunohistochemistry revealed changes in the chemical coding pattern of calbindin-immunoreactive neurons in the inferior mesenteric ganglia of the pig. In control animals, FB/CB-positive neurons were immunoreactive to TH, NPY, SOM, and VIP. In the experimental group, TH-expressing neurons were unaffected, NPY-expressing neurons were increased, whereas the number of neurons immunoreactive to SOM or VIP was reduced. Changes in chemical coding of CB neurons during PE may play an important role in adaptation of these IMG cells under pathological conditions.
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Affiliation(s)
- Joanna Wojtkiewicz
- Department of Neurology and Neurosurgery, Division of Neurosurgery, University of Warmia and Mazury in Olsztyn, Warszawska 30, 10-082 Olsztyn, Poland.
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Cavicchia JC, Fóscolo MR, Palmada N, Delgado SM, Sosa ZY. Involvement of the mesenteric ganglia on androstenedione, noradrenaline and nitrite release using a testis ex vivo system. Endocrine 2012; 41:266-73. [PMID: 22147392 DOI: 10.1007/s12020-011-9568-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2011] [Accepted: 11/11/2011] [Indexed: 10/14/2022]
Abstract
The autonomic nerve fibres converge to the testis along two major pathways, the superior spermatic nerve (SSN) and the inferior spermatic nerve (ISN). The object of this work was to evaluate whether the addition of noradrenaline (NA) in the ganglionic compartment of two ex vivo systems: superior mesenteric ganglion (SMG)-SSN-testis, inferior mesenteric ganglion (IMG)-ISN-testis modulate androstenedione (A₂), NA and nitrite release and to determine whether there are secretory differences between the right and the left testis. Each gonad with its respective ganglion was transferred into a cuvette with two compartments and incubated in a Dubnoff metabolic shaker. The testis incubation liquids were collected and analysed for NA by HPLC, A₂ by RIA and nitrites by the Griess method. When NA is added to the IMG, A₂ and NA release diminishes and nitrite increases in the left testis, while in the right gonad, A₂ and NA increase and nitrite decreases. When NA was administered to the SMG, A₂ and NA increase and nitrite diminishes in the left gonad, but they show opposite fluctuations in the right testis. These ex vivo systems appear to be excellent models for studying the sympathetic ganglionic control of the testis though A₂, NA and nitrite release from the male gonad. It is evident that a better knowledge about the role of catecholamines and nitric oxide in the testis physiology may facilitate the understanding of some reproductive diseases.
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Affiliation(s)
- J C Cavicchia
- Instituto de Histología y Embriología (IHEM)-CONICET, Facultad de Ciencias Médicas, Cuyo Medical School, Universidad Nacional de Cuyo, Post Box 56, 5500 Mendoza, Argentina.
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Koszykowska M, Kozłowska A, Wojtkiewicz J, Skobowiat C, Majewski M, Jana B. Distribution and chemical coding of sympathetic neurons in the caudal mesenteric ganglion projecting to the ovary in sexually mature gilts. Acta Vet Hung 2010; 58:389-403. [PMID: 20713329 DOI: 10.1556/avet.58.2010.3.11] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The distribution and co-localisation patterns of dopamine-beta-hydroxylase (DβH), neuropeptide Y (NPY), somatostatin (SOM) and galanin (GAL) were investigated by use of retrograde neuronal tracing and double-labelling immunofluorescence techniques in the caudal mesenteric ganglion (CaMG) neurons supplying the ovary of adult pigs. The existence and density of nerve fibres that are immunoreactive (IR) for the above-mentioned neuroactive substances were also evaluated. Injections of a fluorescent tracer (Fast Blue; FB) into the ovaries revealed the presence of small- (76.38%) and large-sized (23.62%) FB-positive postganglionic neurons in the CaMG. Noradrenergic FB-positive cells were simultaneously NPY- (43.38%), SOM- (18.77%) and GAL- (18.31%) IR. Of the examined FB-positive neurons, 53.49% were DβH-IR but NPY-immunonegative (IN), 79.06% were DβH-IR but SOM-IN, and 77.16% were DβH-IR but GAL-IN. Small- or large-sized subsets of traced neurons were supplied by only one or a few nerve fibres, exhibiting DβH-, NPY-, SOM- and/or GAL-IR. Our data show the specific morphological as well as immunochemical structural organisation of the sympathetic neurons in the CaMG in adult gilts. The occurrence of an abundant population of noradrenergic perikarya in the CaMG may suggest their important physiological role in the regulation of gonadal function(s) in these animals.
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Affiliation(s)
- Marlena Koszykowska
- 1 Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences Division of Reproductive Endocrinology and Pathophysiology 10-747 Olsztyn Tuwima 10 Poland
| | - Anna Kozłowska
- 1 Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences Division of Reproductive Endocrinology and Pathophysiology 10-747 Olsztyn Tuwima 10 Poland
| | - Joanna Wojtkiewicz
- 2 University of Warmia and Mazury Department of Human Physiology, Faculty of Medical Sciences Olsztyn Poland
| | - Cezary Skobowiat
- 3 University of Warmia and Mazury Division of Clinical Physiology, Department of Functional Morphology, Faculty of Veterinary Medicine Olsztyn Poland
| | - Mariusz Majewski
- 2 University of Warmia and Mazury Department of Human Physiology, Faculty of Medical Sciences Olsztyn Poland
| | - Barbara Jana
- 1 Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences Division of Reproductive Endocrinology and Pathophysiology 10-747 Olsztyn Tuwima 10 Poland
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Sosa ZY, Palmada MN, Fóscolo MR, Capani F, Conill A, Cavicchia JC. Administration of noradrenaline in the autonomic ganglia modifies the testosterone release from the testis using an ex vivo system. ACTA ACUST UNITED AC 2009; 32:391-8. [DOI: 10.1111/j.1365-2605.2008.00927.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Nasser Y, Ho W, Sharkey KA. Distribution of adrenergic receptors in the enteric nervous system of the guinea pig, mouse, and rat. J Comp Neurol 2006; 495:529-53. [PMID: 16498685 DOI: 10.1002/cne.20898] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Adrenergic receptors in the enteric nervous system (ENS) are important in control of the gastrointestinal tract. Here we describe the distribution of adrenergic receptors in the ENS of the ileum and colon of the guinea pig, rat, and mouse by using single- and double-labelling immunohistochemistry. In the myenteric plexus (MP) of the rat and mouse, alpha2a-adrenergic receptors (alpha2a-AR) were widely distributed on neurons and enteric glial cells. alpha2a-AR mainly colocalized with calretinin in the MP, whereas submucosal alpha2a-AR neurons colocalized with vasoactive intestinal polypeptide (VIP), neuropeptide Y, and calretinin in both species. In the guinea pig ileum, we observed widespread alpha2a-AR immunoreactivity on nerve fibers in the MP and on VIP neurons in the submucosal plexus (SMP). We observed extensive beta1-adrenergic receptor (beta1-AR) expression on neurons and nerve fibers in both the MP and the SMP of all species. Similarly, the beta2-adrenergic receptor (beta2-AR) was expressed on neurons and nerve fibers in the SMP of all species, as well as in the MP of the mouse. In the MP, beta1- and beta2-AR immunoreactivity was localized to several neuronal populations, including calretinin and nitrergic neurons. In the SMP of the guinea pig, beta1- and beta2-AR mainly colocalized with VIP, whereas, in the rat and mouse, beta1- and beta2-AR were distributed among the VIP and calretinin populations. Adrenergic receptors were widely localized on specific neuronal populations in all species studied. The role of glial alpha2a-AR is unknown. These results suggest that sympathetic innervation of the ENS is directed toward both enteric neurons and enteric glia.
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Affiliation(s)
- Yasmin Nasser
- Institute of Infection, Immunity and Inflammation and Hotchkiss Brain Institute, Department of Physiology and Biophysics, University of Calgary, Calgary, Alberta T2N 4N1, Canada
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Immediate-early gene expression in the inferior mesenteric ganglion and colonic myenteric plexus of the guinea pig. J Neurosci 1999. [PMID: 10087087 DOI: 10.1523/jneurosci.19-07-02755.1999] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Activation of neurons in the inferior mesenteric ganglion (IMG) was assessed using c-fos, JunB, and c-Jun expression in the guinea pig IMG and colonic myenteric plexus during mechanosensory stimulation and acute colitis in normal and capsaicin-treated animals. Intracolonic saline or 2% acetic acid was administered, and mechanosensory stimulation was performed by passage of a small (0.5 cm) balloon either 4 or 24 hr later. Lower doses of capsaicin or vehicle were used to activate primary afferent fibers during balloon passage. c-Jun did not respond to any of the stimuli in the study. c-fos and JunB were absent from the IMG and myenteric plexus of untreated and saline-treated animals. Acetic acid induced acute colitis by 4 hr, which persisted for 24 hr, but c-fos was found only in enteric glia in the myenteric plexus and was absent from the IMG. Balloon passage induced c-fos and JunB in only a small subset of IMG neurons and no myenteric neurons. However, balloon passage induced c-fos and JunB in IMG neurons (notably those containing somatostatin) and the myenteric plexus of acetic acid-treated animals. After capsaicin treatment, c-fos and JunB induction by balloon passage was inhibited in the IMG, but there was enhanced c-fos expression in the myenteric plexus. c-fos and JunB induction by balloon stimulation was also mimicked by acute activation of capsaicin-sensitive nerves. These data suggest that colitis enhances reflex activity of the IMG by a mechanism that involves activation of both primary afferent fibers and the myenteric plexus.
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Browning KN, Zheng Z, Kreulen DL, Travagli RA. Two populations of sympathetic neurons project selectively to mesenteric artery or vein. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 276:H1263-72. [PMID: 10199851 DOI: 10.1152/ajpheart.1999.276.4.h1263] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The objective of this study was to determine whether sympathetic neurons of the inferior mesenteric ganglion (IMG) projecting to mesenteric arteries could be distinguished by their localization, neurochemical phenotype, and electrophysiological properties from neurons projecting to mesenteric veins. In an in vitro intact vasculature-IMG preparation, neurons were labeled following intraluminal injection of Fluoro-Gold or rhodamine beads into the inferior mesenteric artery (IMA) or vein (IMV). The somata of neurons projecting to IMA were localized in the central part of the IMG, whereas those projecting to IMV were localized more peripherally. None of the labeled neurons was doubly labeled. Neuropeptide Y immunoreactivity was found in 18.9% of neurons innervating the IMA, but not in neurons innervating the IMV. Identified neurons were dissociated and characterized using whole cell patch-clamp recording. After direct soma depolarization, all of the labeled arterial and venous neurons were classified as tonic firing, compared with only 40% of unlabeled neurons; the remaining 60% of unlabeled neurons were phasic firing. The results indicate that IMG neurons projecting to mesenteric arteries are distinct from neurons projecting to mesenteric veins.
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Affiliation(s)
- K N Browning
- Gastroenterology Research, Henry Ford Health Sciences Center, Detroit 48202, Michigan, USA
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Mizhorkova Z, Milusheva E, Papasova M. Involvement of nitric oxide in extrinsic nervous control of ileal contractile activity. Brain Res Bull 1998; 47:151-4. [PMID: 9820732 DOI: 10.1016/s0361-9230(98)00069-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The experiments were carried out on guinea pig mesenteric nerve-ileal preparations (ileal segments with mesenteric nerves originating from the superior mesenteric ganglion) isolated at various distances from the ileocecal junction (ICJ). Contractile activity was recorded in the presence of hexamethonium (50 microM). On the background of electrical field stimulation (EFS; 0.1 Hz, 0.5 ms, supramaximal current intensity)-induced twitch contractions, the mesenteric nerve stimulation (MNS; frequency of 2-30 Hz, 0.5 ms, supramaximal current intensity, 20-s trains) exerted two types of effects, depending on the distance from ICJ at which the preparations were isolated and on the pulse frequency. In preparations isolated from the ileum at a distance of 20 cm from ICJ, MNS at all the frequencies studied inhibited the EFS-induced twitch contractions, reaching the maximum at 30 Hz. In preparations isolated from the terminal ileum at a distance of 10 cm from ICJ, MNS at 20 Hz and 30 Hz decreased the twitch contraction amplitude, whereas MNS at 2-10 Hz produced an increase in the tone on which twitch contractions with reduced amplitude were superimposed. The finding that guanethidine (5 microM) eliminated the MNS twitch inhibition provides evidence for the adrenergic origin of the latter. The nitric oxide synthase inhibitor Nomega-nitro-L-arginine (100 microM) was efficient in reducing the MNS twitch inhibition but only at low-frequency (5 Hz) MNS (p < 0.05). Our results suggest the participation of nitric oxide in the nervous control exerted by the superior mesenteric ganglion over the ileal contractile activity.
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Affiliation(s)
- Z Mizhorkova
- Institute of Physiology, Bulgarian Academy of Sciences, Sofia.
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Morris JL, Grasby DJ, Anderson RL, Gibbins IL. Neurochemical distinction between skeletal muscle vasodilator neurons and pelvic vasodilator neurons in guinea-pigs. JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM 1998; 71:64-8. [PMID: 9722196 DOI: 10.1016/s0165-1838(98)00056-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
This study sets out to compare the combinations of potential vasodilator transmitters expressed by sympathetic and pelvic vasodilator neurons of guinea-pigs. Triple-labelling fluorescence immunohistochemistry was used to examine immunoreactivity (IR) to vasoactive intestinal peptide (VIP), nitric oxide synthase (NOS) and calcitonin gene-related peptide (CGRP) in lumbar sympathetic ganglia, and in perivascular axons supplying hindlimb skeletal muscles or pelvic viscera. Only 0.2% of VIP-IR nerve cell bodies in lumbar sympathetic ganglia (n = 4632 VIP-IR nerve cell profiles) contained NOS-IR, and one VIP-IR neuron contained CGRP-IR. The VIP-IR perivascular axons along the common and external iliac arteries, femoral artery and arteries to hindlimb muscles lacked NOS-IR and CGRP-IR. In contrast, all VIP-IR perivascular axons projecting from pelvic ganglia to the main uterine artery, and half of the VIP-IR axons along the internal iliac artery, contained NOS-IR and CGRP-IR. Thus, the neurochemical content of sympathetic vasodilator neurons to skeletal muscle arteries was clearly distinguishable from that of pelvic vasodilator neurons to the uterine vasculature. Furthermore, the autonomic dilation in each vascular bed is likely to be qualitatively different, and matched to the functional requirements of each target organ.
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Affiliation(s)
- J L Morris
- Centre for Neuroscience and Department of Anatomy and Histology, Flinders University of South Australia, Adelaide, Australia.
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Zheng Z, Shimamura K, Anthony TL, Travagli RA, Kreulen DL. Nitric oxide is a sensory nerve neurotransmitter in the mesenteric artery of guinea pig. JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM 1997; 67:137-44. [PMID: 9479665 DOI: 10.1016/s0165-1838(97)00100-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Previous studies have shown that the guinea pig inferior mesenteric artery receives spinal sensory vasodilatory innervation, which can be activated by colon distention and electrical nerve stimulation. In the present study, we investigated the hypotheses that nitric oxide synthase (NOS) is present in guinea pig primary sensory neurons in the dorsal root ganglion (DRG) and in nerve fibers surrounding the mesenteric arteries, and that nitric oxide (NO) is a sensory neurotransmitter in the inferior mesenteric artery in vitro. Double-labeling immunohistochemistry showed that neuronal NOS-IR was found in 12% of cells of guinea pig thoracic and lumbar DRGs; in 95.1% of these cells it was colocalized with substance P (SP), and SP immunoreactivity (SP-IR) was present in 23% of cells of the same DRGs. Neuronal NOS-like immunoreactivity was localized in nerve fibers surrounding guinea pig mesenteric artery and 25% of them were double stained with SP-IR. Endothelium-denuded inferior mesenteric artery preparations in vitro were incubated with guanethidine (30 microns, 30 min) and pre-contracted with methoxamine (30 microns). The NO donors, sodium nitroprusside (1 micron) and L-nitrosocysteine (300 microns), produced 91.0 +/- 5.5 and 90.4 +/- 9.6% vasodilatation of total vasodilatation in the vessel segments, respectively, which was capsaicin- or tetrodotoxin-insensitive. Repetitive electrical field stimulation of the preparations produced a frequency-dependent vasodilatation which was reduced by pretreatment with capsaicin or by tetrodotoxin (10 microns). The NOS inhibitor N omega-nitro-L-arginine (L-NNA) (100 microns, 30 min) diminished the nerve-evoked vasodilatation from 41.8 +/- 8.4 to 21.4 +/- 9.7% at 2 Hz and from 50.8 +/- 5.6 to 19.0 +/- 7.3% at 15 Hz (P < 0.05), whereas NG-nitro-L-arginine methyl ester (L-NAME, 100 microns-1 mM) did not significantly inhibit the relaxation. The stereo isomer nitro-D-arginine (D-NNA, 100 microns, 30 min) was ineffective. These findings suggest that NO is a neurotransmitter released from primary sensory nerves which mediates vasodilation in vitro.
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Affiliation(s)
- Z Zheng
- Department of Physiology, School of Medicine, West Virginia University, Morgantown 26506, USA
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