Distribution of enteric neurons showing immunoreactivity for substance P in the guinea-pig ileum

Costa, M.; Cuello, A. Claudio; Furness, John B.; Franco, R.

doi:10.1016/0306-4522(80)90108-6

Cited by 195 publications

(40 citation statements)

References 21 publications

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“…la). The distribution of SP-immunoreactive fibers in the myenteric ganglia, in the internodal strands connecting the myenteric ganglia and in the meshwork of the tertiary myenteric plexus was similar to that reported previously (e.g., Costa et al, 1980). In 1 pm sections through ganglia labeled for electron microscopy ( Fig.…”

Section: Resultssupporting

confidence: 88%

Ultrastructural analysis of substance P-immunoreactive nerve fibers in myenteric ganglia of guinea pig small intestine

1989

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Electron microscopic immunocytochemistry has been used to study the distribution and synaptic relationships of substance P (SP)- immunoreactive nerve fibers in ultrathin sections from whole-mount preparations of myenteric ganglia from guinea pig small intestine. At the light microscopic level, myenteric ganglia stained for ultrastructural study contained dense arrays of SP-immunoreactive nerve fibers around and between the neuronal and glial cell bodies. At the electron microscopic level, SP-containing nerve fiber profiles occurred throughout the neuropil of the myenteric ganglia. Both vesicle- containing and nonvesiculated nerve fiber profiles were immunoreactive. The positive vesiculated profiles contained variable proportions of small clear and large granular vesicles. Two-thirds of the vesicle- containing nerve fiber profiles in myenteric ganglia were immunoreactive for SP. Many vesiculated SP-immunoreactive nerve fiber profiles were directly apposed to each myenteric neuron. However, only about 0.6% of these vesiculated profiles formed synapses that showed the ultrastructural specializations of vesicle clustering presynaptically and fuzzy electron-dense material on the postsynaptic membrane. On the other hand, morphologically identifiable synapses with SP-immunoreactivity comprised about half the total number of synapses in the ganglia. SP-immunoreactive synapses were observed on nonvesiculated nerve processes in the periphery of the ganglia and on nerve cell bodies. Most of the axosomatic SP synapses occurred on small neurons that lay either on the surfaces of the ganglia or near the fibers of the internodal strands where they traveled through the ganglia. Both SP-positive and SP-negative nerve cell bodies received SP synapses.(ABSTRACT TRUNCATED AT 250 WORDS)

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Section: Resultssupporting

confidence: 88%

Ultrastructural analysis of substance P-immunoreactive nerve fibers in myenteric ganglia of guinea pig small intestine

1989

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“…Most of the substance P-containing neurones in the gut seem to be of intrinsic origin (Costa et al 1980(Costa et al , 1981Jessen, Saffrey, van Noorden, Bloom, Polak & Burnstock, 1980), and systemic treatment of rats and guinea-pigs with capsaicin does not change the content of radioimmunoassayable substance P in the intestine Gamse et al 1981;Buck, Desmukh, Yamamura & Burks, 1981). Immunohistochemical investigations have, however, shown that the gut is also innervated by extrinsic, probably sensory, substance P fibres which run in the mesenteric nerves (Costa et al 1980(Costa et al ,1981. More recently Furness, Papka, Della, Costa & Eskay (1982) have demonstrated that these extrinsic fibres are depleted of substance P by systemic treatment with capsaicin.…”

Section: Discussionmentioning

confidence: 99%

Evidence that the contractile response of the guinea‐pig ileum to capsaicin is due to release of substance P.

Barthó

Holzer

Lembeck

et al. 1982

The Journal of Physiology

113

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SUMMARY1. The possible roles of substance P and opioids in the contractile response of the isolated guinea-pig ileum to the sensory stimulant drug capsaicin were investigated, and the contractions were found to be inhibited by about 60% in preparations desensitized to substance P. The results indicate that the contractile response of the guinea-pig ileum to capsaicin and mesenteric nerve stimulation is mediated by release of substance P, presumably from sensory nerve endings in the gut. Substance P appears to act on the smooth muscle both directly and indirectly via cholinergic neurones. It is proposed that opioids modulate the non-cholinergic response to capsaicin by inhibiting the release of substance P.

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“…In the present experiments, low concentrations of SP (10-10-10-9M) enhanced the amplitude of e.j.ps with no change in membrane potential and membrane resistance. SP is present in intrinsic neurones of the gut (Schultzberg, Dreyfus, Gershon, H6kfelt, Elde, Nilsson, Said & Golstein, 1978), and a considerable number of these fibres seems to innervate the muscle layer of the intestine (Costa, Cuello, Furness & Franco, 1980). Thus, the possibility that endogenous SP acts on the cholinergic nerve terminals to enhance the transmitter release cannot be ruled out.…”

Section: Effects Of Substance P In the Presence Of Baclofenmentioning

confidence: 99%

The Effects of Substance P on Smooth Muscle Cells and on Neuro‐effector Transmission in the Guinea‐pig Ileum

Fujisawa¹,

Ito²

1982

British J Pharmacology

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The effects of substance P (SP) on the membrane and contractile properties of the smooth muscle cell, or on neuro‐effector transmission in the guinea‐pig ileum were observed by means of microelectrodes, double sucrose gap and tension recording. SP (10−13‐10−10 M) induced a phasic contraction of longitudinal muscle strips, but did not change the muscle tone of circular muscle strips, in concentrations up to 10−8 M. SP (1010‐10‐8M) evoked three different membrane responses in longitudinal muscle cells: (i) bursts of spike discharges with no significant change in the membrane potential and input membrane resistance; (ii) bursts of spike discharges with a small but clear depolarization of the membrane and increase in the input membrane resistance; (iii) slow waves with no change in the membrane potential. In the circular muscle cells, low concentrations of SP (< 10−8M) did not affect the membrane potential or the spikes, but SP (10−7M) increased the spike discharges with no significant change in the membrane potential. SP (10−10M) reduced the threshold depolarization required for the generation of action potentials with no change in membrane potential of the longitudinal muscle cells. Pretreatment with atropine (5 × 10−6M), tetrodotoxin (TTX 10−6M) or baclofen (4.7 × 10−6M) had no effect on the excitatory actions of SP on the smooth muscle cells of longitudinal and circular muscle strips. Excitatory actions of SP on the membrane potential or spike activities of longitudinal muscle cells were preserved in NaCl but not in Ca‐deficient solution. SP (10−10‐10−9M) enhanced the amplitude of the excitatory junction potentials (e.j.ps) evoked by electrical field stimulation in longitudinal muscle cells with no change in the membrane potential and input resistance. SP (10−10‐10−9M), however, did not change the amplitude of inhibitory junction potentials (i.j.ps) recorded from the circular muscle cells. These results indicate that SP in relatively low concentrations acts on both smooth muscle cells and on excitatory neuro‐effector transmission in the longitudinal muscle; the main site of the action of SP is probably the muscle membrane.

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Distribution of enteric neurons showing immunoreactivity for substance P in the guinea-pig ileum

Cited by 195 publications

References 21 publications

Ultrastructural analysis of substance P-immunoreactive nerve fibers in myenteric ganglia of guinea pig small intestine

Ultrastructural analysis of substance P-immunoreactive nerve fibers in myenteric ganglia of guinea pig small intestine

Evidence that the contractile response of the guinea‐pig ileum to capsaicin is due to release of substance P.

The Effects of Substance P on Smooth Muscle Cells and on Neuro‐effector Transmission in the Guinea‐pig Ileum

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