Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P20366 (substance P)
 21,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Intracellular recordings of membrane potential and membrane currents were made from neurones in the submucous plexus of the guinea-pig caecum in vitro. Fast and slow excitatory postsynaptic potentials and slow inhibitory postsynaptic potentials were recorded from the majority of neurones following focal stimulation of presynaptic fibres in the plexus. The slow inhibitory postsynaptic potential was associated with an increase in membrane conductance and reversed its polarity at -90 mV; it was reversibly blocked by yohimbine. The slow excitatory postsynaptic potential and its underlying current was associated with a decrease in membrane conductance. Two kinds of voltage-dependence both of the slow excitatory postsynaptic potential and current were observed; in 80% of cells, the excitatory postsynaptic potential and current became smaller with membrane hyperpolarization and reversed polarity at -90 mV (reversing type) but in 20% of cells both the excitatory postsynaptic potential and current simply disappeared when the membrane potential reached -70 mV (non-reversing type). The effects of acetylcholine, adenosine 5'-triphosphate, bombesin, 5-hydroxytryptamine, neurotensin, noradrenaline, substance P and vasoactive intestinal polypeptide were examined. The only substance which mimicked the slow inhibitory postsynaptic potential was noradrenaline; brief applications of noradrenaline caused hyperpolarizations which had the same time-course, reversal potential and sensitivity to yohimbine as the slow inhibitory postsynaptic potential. The non-reversing type of slow excitatory postsynaptic potential was mimicked only by adenosine 5'-triphosphate. The reversing type of slow excitatory postsynaptic potential was mimicked by bombesin, neurotensin, substance P and vasoactive intestinal polypeptide. 5-Hydroxytryptamine and vasoactive intestinal polypeptide (in some neurones) caused a depolarization with an increase in membrane conductance. All three synaptic potentials were reversibly depressed by superfusion of noradrenaline but noradrenaline did not affect the potential changes evoked by brief application of exogenous acetylcholine or substance P. It is concluded that, in guinea-pig submucous plexus neurones, the slow inhibitory postsynaptic potential is mediated by noradrenaline and results from a potassium conductance increase.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Slow postsynaptic potentials in neurones of submucous plexus of guinea-pig caecum and their mimicry by noradrenaline and various peptides. 241 86

To determine if chemicals produced endogenously within the gastrointestinal system stimulate abdominal visceral sensory endings, we recorded the response of 42 A- and 25 C-fibers in the splanchnic nerve of cats as substance P (10-20 micrograms), 5-hydroxytryptamine (5-HT, 100-200 micrograms), or bradykinin (10 micrograms) was injected into the descending thoracic aorta. Approximately half of the sensory endings responded to each chemical. However, significantly more C- than A-fiber endings responded to 5-HT (64 vs. 39%) and bradykinin (76 vs. 41%). Most C-fiber endings were insensitive to external mechanical stimuli, supporting the concept that these endings are primarily chemosensitive. In contrast, most A-fiber endings were quite sensitive to external mechanical stimuli. Additionally, more A-fiber endings located in contractile (gut or vasculature) than in noncontractile (pancreas, liver, or spleen) regions responded to 5-HT (58 vs. 19%), bradykinin (67 vs. 15%), and substance P (57 vs. 29%), a response that frequently occurred coincident with the development of chemically induced gut contractions. Thus many A-fiber endings are primarily sensitive to mechanical stimuli. However, 15-30% of the A-fiber endings located in noncontractile regions responded to chemicals, although the endings likely were removed from the mechanical effects of these chemicals. Since these A-fiber endings are also quite sensitive to external mechanical stimuli, they may be polymodal in their function. We conclude that abdominal visceral sensory endings are not homogeneous in function and are stimulated by several chemicals produced endogenously within the gastrointestinal system, including substance P, 5-HT, and bradykinin.
 ...
PMID:Substance P, 5-hydroxytryptamine, and bradykinin stimulate abdominal visceral afferents. 2420 60

Substance P, administered intrathecally in the lumbar area of paraplegic rats activated the electromyogram (EMG) of the hindlimbs. This effect was markedly enhanced by previous denervation by 5,7-dihydroxytryptamine. Stimulation of the motoneurons by substance P was followed by a blunted response to the excitatory substances thyrotropin releasing hormone (TRH) and 5-hydroxytryptophan (5-HTP), given intraperitoneally 1 hr later. The decreased sensitivity to 5-HTP persisted for more than 24 hr. In several animals, however, a flaccid paralysis was observed after administration of substance P. In such cases the response to 5-HTP was enhanced 24 hr later. These observations suggest an interaction between 5-HT, TRH and substance P in the control of the excitability of motoneurons.
 ...
PMID:Substance P in the lumbar spinal cord of the rat affects the motor response to 5-HTP and TRH. 242 10

In this study we examined the possibility that serotonin (5-HT) and substance P (SP) coexist in fibers and terminals afferent to sympathoadrenal preganglionic (SAP) neurons in the intermediolateral cell column (IML) of the spinal cord. SAP neurons in the IML were identified by retrograde labeling with either Fast Blue or True Blue injected into the adrenal medulla of rats. A simultaneous immunofluorescent double labeling technique was used to identify both 5-HT- and SP-like immunoreactivity in single tissue sections. Labeled SAP neurons were observed which were apposed by fibers immunoreactive for either neurotransmitter, as well as SAP neurons apposed by neither 5-HT- nor SP-like immunoreactive structures. In addition, 5-HT- and SP-like immunoreactivity were observed in separate fibers apposing the same labeled neuron and coexisting in fibers and terminal appearing in apposition to labeled SAP neurons. These data suggest a complex interaction by these neurotransmitters in regulating sympathetic outflow and may provide a model for interpreting conflicting observations concerning the effects of local 5-HT administration on sympathetic nerve activity.
 ...
PMID:Coexistence of serotonin- and substance P-like immunoreactivity in nerve fibers apposing identified sympathoadrenal preganglionic neurons in rat intermediolateral cell column. 242 25

Primate spinal cord tissue sections were sequentially incubated in serotonin (5-HT), substance P (SP) and methionine-enkephalin antisera and reacted immunocytochemically. The findings indicate that virtually all SP-like immunoreactivity coexists with 5-HT in the ventral horn, while an additional group of 5-HT terminals do not contain SP immunoreactivity.
 ...
PMID:Serotonergic and peptidergic inputs to the primate ventral spinal cord as visualized with multiple chromagens on the same tissue section. 242 90

The mudpuppy cardiac ganglion contains 2 neuron types: large parasympathetic postganglionic projection neurons and smaller intrinsic neurons originally described by McMahan and Purves (1976) as intensely fluorescent (SIF) cells. The function of these SIF cells, present in the mudpuppy cardiac ganglion, is unknown. Further, direct application of catecholamines, which are thought to be contained in SIF cells, to the parasympathetic postganglionic cells has no effect (Hartzell et al., 1977). As SIF cells in other ganglion preparations recently have been shown to contain putative transmitter substances in addition to catecholamines, immunocytochemical experiments were conducted to test for the presence of additional transmitter substances in the SIF cells within the cardiac ganglion. Whole-mount septal preparations were dissected from Necturus maculosus and processed for indirect immunocytochemistry. The results indicated that many of these intrinsic neurons contained 5-HT or a substance P-like peptide, or both. Many small intrinsic neurons which contain either substance P or 5-HT were also positive for aqueous-aldehyde-induced fluorescence, indicating the presence of a catecholamine. Finally, some of these cells appeared to contain all 3: a catecholamine, 5-HT, and a substance P-like peptide.
 ...
PMID:Catecholamine, serotonin, and substance P-like peptide containing intrinsic neurons in the mudpuppy parasympathetic cardiac ganglion. 242 25

Regulation of the release of substance P (SP) by the coexisting neurotransmitter serotonin (5-hydroxytryptamine, 5-HT) in the ventral spinal cord and the effects of chronic antidepressant treatment mediated changes in serotonin metabolism on the regulation, were examined. The K+ (40 mmol/l) evoked release of (SP) from slices of the ventral spinal cord of the rat was potentiated by (5-HT) applied to 100 mumol/l concentration. This effect was blocked by the serotoninergic antagonists methysergide (10 mumol/l), methiotepin (10 mumol/l) and fully blocked by ketanserin (10 mumol/l). Thus the 5-HT receptor which regulates the release of SP appears to belong to the type-2 5-HT receptors. Chronic treatment with the selective serotonin uptake inhibitor zimelidine (14 days, 2 X 10 mumol/kg/day, p.o.) lowered the tissue levels of the 5-HT metabolite: 5-hydroxyindol acetic acid (5-HIAA) and elevated the tissue levels of SP in both the ventral and dorsal spinal cord as compared to that in the vehicle treated group (14 days, 2 X 5 ml saline/kg/day, p.o.). The decrease in the 5-HIAA levels after chronic zimelidine treatment was quantitatively similar in the dorsal (33%, p less than 0.01) and ventral (31%, p less than 0.05) spinal cord. The increase in SP levels after chronic zimelidine treatment was more pronounced in the ventral cord (80%, p less than 0.01) where the majority of the SP containing nerve endings also contain 5-HT, than in the dorsal spinal cord (22% increase in SP, p less than 0.05), where only a minor fraction of the SP-containing nerve endings shows a 5-HT/SP coexistence.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Serotonin type-2 receptor mediated regulation of substance P release in the ventral spinal cord and the effects of chronic antidepressant treatment. 242 4

It has been shown that substance P(SP), as well as its carboxy and amino terminal fragments, affects a wide range of behaviors. In order to test the CNS activity of these fragments, we measured their effects on passive avoidance learning and monoamine activity. Following one-trial passive avoidance training, mice were injected intraventricularly with either a carboxy or amino terminal SP fragment (SP-C or SP-N), SP itself or phosphate-buffered saline (PBS). SP-N enhanced avoidance retention, which was tested 24 h after training. In a second experiment, monoamine activity was measured one hour after intraventricular injection of SP, PBS or SP fragments. SP-C decreased both nigral 5-hydroxyindoleacetic acid/5-hydroxytryptamine (5-HIAA/5-HT) and, to a lesser extent, 3,4-dihydroxyphenylacetic acid/dopamine, while SP-N increased nigral 5-HIAA/5-HT. It was concluded that SP-N and SP-C can exert behavioral and neurochemical effects that may be independent of the parent SP molecule.
 ...
PMID:The effect of substance P and its fragments on passive avoidance retention and brain monoamine activity. 242 83

The cholinergic and noncholinergic-nonadrenergic (NCNA) excitatory and inhibitory responses of the guinea-pig ileum to transmural nerve stimulation (TNS) were studied. Unlike the contraction induced by histamine and acetylcholine the responses to TNS, ATP, substance P, bradykinin, 5-HT and GABA were not sustained. The contraction and its fading during TNS involved the activation of cholinergic, adrenergic and NCNA neurons. Substance P, 5-HT and ATP desensitization resulted in reduction of the excitatory NCNA response whereas that due to bradykinin attenuated both the excitatory and inhibitory NCNA responses. The desensitization against TNS and the potential transmitters studies was selective except in the case of ATP. The present results suggest that it is unlikely that ATP, bradykinin or GABA would be the NCNA transmitters in the guinea-pig ileum. The cross-desensitization between the excitatory NCNA transmitter on the one hand, and substance P (markedly expressed) and 5-HT (slightly expressed) on the other hand, give further evidence in favor of the possible transmitter role of substance P-like peptide in excitatory NCNA transmission and of the role of 5-HT in the activation of NCNA neurons.
 ...
PMID:Effect of desensitization induced by adenosine 5'-triphosphate, substance P, bradykinin, serotonin, gamma-aminobutyric acid and endogenous noncholinergic-nonadrenergic transmitter in the guinea-pig ileum. 242 32

The synaptic relationship between spinal cord central gray projection neurons and immunocytochemically identified afferents in the rat were examined at the light microscopic level using the combined techniques of retrogradely transported True blue and serotonin (5-HT), enkephalin (ENK), and substance P (SP) immunocytochemistry. At L4-L6, numerous retrogradely labeled neurons could be identified around the central canal after large bulbar injections of True blue. Of these projection neurons, 75% were apposted by 5-HT varicosities, 57% by ENK varicosities and 58% by SP varicosities. Hemisection of the spinal cord produced a marked reduction in the amount of 5-HT immunoreactivity and the number of putative 5-HT contacts observed on neurons of the spinal cord central gray. A small decrease in SP immunoreactivity and putative contacts was seen after dorsal rhizotomy. Neither rhizotomy nor hemisection produced discernable changes in ENK immunofluorescence. Based on the distributions of 5-HT, ENK and SP in the spinal cord, we suggest that a more precise delineation of lamina X in the rat can be made according to immunocytochemical rather than strictly morphological criteria.
 ...
PMID:Neurochemical identification of afferents onto spinomedullary neurons in the rat spinal cord central gray matter. 243 92


<< Previous 1 2 3 4 5 6 7 8 9 10