Peptides as Neurotransmitters in Vascular Autonomic Neurons

Morris, J.L.

doi:10.1111/j.1440-1681.1995.tb01938.x

Cited by 12 publications

(15 citation statements)

References 109 publications

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“…Peptide mediators such as substance P, pituitary adenylate cyclase-activating polypeptide, and VIP (10,25,29,30,51) are released at higher frequencies of electrical field stimulation (EFS) of enteric and autonomic nerves. We chose EFS stimulus parameters (50 V/cm, 0.5 ms, 5 pps) that minimize the release of peptide mediators.…”

mentioning

confidence: 99%

Do gap junctions play a role in nerve transmissions as well as pacing in mouse intestine?

Daniel

El-Yazbi²,

Mannarino³

et al. 2007

American Journal of Physiology-Gastrointestinal and Liver Physi

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Varicosities of nitrergic and other nerves end on deep muscular plexus interstitial cells of Cajal or on CD34-positive, c- kit-negative fibroblast-like cells. Both cell types connect to outer circular muscle by gap junctions, which may transmit nerve messages to muscle. We tested the hypotheses that gap junctions transmit pacing messages from interstitial cells of Cajal of the myenteric plexus. Effects of inhibitors of gap junction conductance were studied on paced contractions and nerve transmissions in small segments of circular muscle of mouse intestine. Using electrical field stimulation parameters (50 V/cm, 5 pps, and 0.5 ms) which evoke near maximal responses to nitrergic, cholinergic, and apamin-sensitive nerve stimulation, we isolated inhibitory responses to nitrergic nerves, inhibitory responses to apamin-sensitive nerves and excitatory responses to cholinergic nerves. 18β-Glycyrrhetinic acid (10, 30, and 100 μM), octanol (0.1, 0.3, and 1 mM) and gap peptides (300 μM of40Gap27,43Gap26,37,43Gap27) all failed to abolish neurotransmission. 18β-Glycyrrhetinic acid inhibited frequencies of paced contractions, likely owing to inhibition of l-type Ca2+channels in smooth muscle, but octanol or gap peptides did not. 18β-Glycyrrhetinic acid and octanol, but not gap peptides, reduced the amplitudes of spontaneous and nerve-induced contractions. These reductions paralleled reductions in contractions to exogenous carbachol. Additional experiments with gap peptides in both longitudinal and circular muscle segments after NG-nitro-l-arginine and TTX revealed no effects on pacing frequencies. We conclude that gap junction coupling may not be necessary for pacing or nerve transmission to the circular muscle of the mouse intestine.

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confidence: 99%

Do gap junctions play a role in nerve transmissions as well as pacing in mouse intestine?

Daniel

El-Yazbi²,

Mannarino³

et al. 2007

American Journal of Physiology-Gastrointestinal and Liver Physi

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“…3) (n = 12). This class of axons was taken to reflect processes of sensory nerves [17, 20, 26, 27]. Very rarely, SP-IR axons without CGRP-IR were detected.…”

Section: Resultsmentioning

confidence: 99%

“…3A–C) (n = 15). This TH-IR class of nerves was taken to reflect sympathetic, noradrenergic axons [17, 26]. A second population of perivascular axons contained VIP-IR, with many of these also containing NPY-IR (fig.…”

Section: Resultsmentioning

confidence: 99%

“…2C, D) (n = 12), but not TH-IR or CGRP-IR. This VIP-IR class of axons was taken to reflect autonomic vasodilator nerves [17, 26]. Axons with VIP-IR in the cheek pouch and retractor muscle consistently (n = 6) lacked NOS-IR (fig.…”

Section: Resultsmentioning

confidence: 99%

“…Neuropeptides are present in the majority of autonomic neurons and in some sensory neurons projecting to mammalian blood vessels, and form an important component of the repertoire of neurotransmitters used to regulate regional blood flow [15, 16, 17]. Furthermore, use of multiple-labelling fluorescence immunohistochemistry can define different populations of vasomotor neurons on the basis of their neurochemical content.…”

Section: Introductionmentioning

confidence: 99%

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Heterogeneity of Vascular Innervation in Hamster Cheek Pouch and Retractor Muscle

Grasby

Morris²,

Segal³

1999

J Vasc Res

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The hamster cheek pouch and its retractor muscle have provided valuable insights into microvascular physiology of an epithelial tissue and striated muscle, respectively. Nevertheless, the innervation of these vascular beds has not been resolved. This study has investigated the nature of autonomic and sensory innervation of these vascular beds and has tested whether it varies within or between tissues. Multiple-labelling immunohistochemistry identified autonomic and peptide-containing sensory nerve fibres. Presumptive sympathetic vasoconstrictor axons with immunoreactivity (IR) for tyrosine hydroxylase (TH) and neuropeptide Y (NPY) innervated feed arteries and arterioles (but not veins or venules) of the retractor and anterior (muscular) cheek pouch; these axons were absent from the posterior (epithelial) region of the cheek pouch, as confirmed by catecholamine fluorescence. Presumptive autonomic vasodilator axons with IR for vasoactive intestinal peptide (VIP) consistently innervated feed arteries and proximal arterioles of the cheek pouch, but generally not those of the retractor muscle nor distal arterioles of either tissue. Sparse presumptive sensory axons with IR for calcitonin gene-related peptide (CGRP) and substance P were found near arterial and venous vessels in all regions of the cheek pouch and retractor muscle; CGRP-IR was also located in motor end plates associated with striated muscle fibres. Such regional differences in vascular innervation by autonomic and sensory neurons may selectively effect local and regional control of blood flow between and within vascular beds.

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