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Query: UNIPROT:P20366 (
substance P
)
21,176
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Inflammation in the joint causes peripheral sensitization (increase of sensitivity of nociceptive primary afferent neurons) and central sensitization (hyperexcitability of nociceptive neurons in the central nervous system). The processes of sensitization are thought to be the basis of arthritic pain that appears as spontaneous pain (joints at rest) and hyperalgesia (augmented pain response on noxious stimulation and pain on normally nonpainful stimulation). Sensitization also facilitates efferent neuronal processes through which the nervous system influences the inflammatory process. Peripheral sensitization is produced by the action of inflammatory mediators such as bradykinin, prostaglandins, neuropeptides, and cytokines which activate corresponding receptors in proportions of nerve fibers. In addition, the expression of receptors, for example, bradykinin and
neurokinin 1
receptors, is upregulated during inflammation. The development of hyperexcitability of spinal cord neurons is produced by various transmitter/receptor systems that constitute and modulate synaptic activation of the neurons. The key transmitter is glutamate that activates N-methyl-d-aspartate (NMDA) and non-NMDA receptors on spinal cord neurons. Blockade of these receptors prevents and reduces central sensitization. Excitatory neuropeptides (
substance P
and calcitonin gene-related peptide) further central sensitization. Central sensitization also is facilitated by mediators that have complex actions (e.g., prostaglandin E(2)). Spinal
PGE
(2) binds to receptors at presynaptic endings of primary afferent neurons (thus influencing synaptic release) and to receptors on postsynaptic spinal cord neurons. The administration of
PGE
(2) to the spinal cord surface produces changes of responsiveness of spinal neurons similar to peripheral inflammation, and spinal indomethacin to the spinal cord attenuates development of hyperexcitability significantly.
...
PMID:Mechanisms of pain in arthritis. 1211 91
Interaction between
substance P
(SP) and
PGE
(2) on Cl(-) secretion in the guinea pig distal colonic epithelia was investigated. A short-circuit current (I(sc)) was measured as an index of ion transport. Mucosa preparations deprived of muscle and submucosa of distal colon were mounted in the Ussing flux chamber and treated with TTX and piroxicam to remove the influences of neuronal activity and endogenous PG synthesis, respectively. Although SP (10(-7) M) itself evoked little increase in I(sc), exogenous
PGE
(2) concentration dependently enhanced the response of SP. The effect of
PGE
(2) on the SP-evoked response was mimicked by forskolin and 8-bromoadenosine cAMP. Depletion of Ca2+ from the bathing solution reduced the
PGE
(2)-dependent response of SP. Effects of
PGE
(2), SP, and SP in the presence of
PGE
(2) on intracellular Ca2+ concentration ([Ca2+](i)) in isolated crypt cells were measured by the confocal microscope fluorescence imaging system. SP, but not
PGE
(2), temporally evoked an increase in [Ca2+](i) but declined to the baseline within 3 min. A return of the SP-evoked increase in [Ca2+](i) was slower in the presence of
PGE
(2) than SP alone. These results suggest that
PGE
(2) synergistically enhances SP-evoked Cl(-) secretion via an interaction between the intracellular cAMP and [Ca2+](i) in the epithelial cells. In conclusion, SP and
PGE
(2) could cooperatively induce massive Cl(-) secretion in guinea pig distal colon at epithelial levels.
...
PMID:Substance P-evoked Cl(-) secretion in guinea pig distal colonic epithelia: interaction with PGE(2). 1212 82
Increasing renal pelvic pressure results in
PGE
(2)-mediated release of
substance P
.
Substance P
increases afferent renal nerve activity (ARNA), which leads to a reflex increase in urinary sodium excretion (U(Na)V). Endogenous ANG II modulates the responsiveness of renal mechanosensory nerves. The ARNA and U(Na)V responses are suppressed by low- and enhanced by high-sodium diet. We examined whether the ARNA responses are altered in rats with congestive heart failure (CHF), a condition characterized by increased ANG II and sodium retention. The ARNA responses to increasing renal pelvic pressure </=7.5 mmHg were suppressed in CHF vs. sham-CHF rats fed normal sodium diet. In CHF rats, increasing renal pelvic pressure 2.5 and 7.5 mmHg increased ARNA 0 +/- 1 and 13 +/- 2% (P < 0.01) before and 9 +/- 1 (P < 0.01) and 19 +/- 1% (P < 0.01) during renal pelvic perfusion with losartan. Losartan had no effect on the ARNA responses in sham-CHF rats. In isolated renal pelvises from CHF rats,
PGE
(2) increased
substance P
release from 11 +/- 2 to 15 +/- 3 pg/min (not significant) without and from 16 +/- 2 to 30 +/- 4 pg/min (P < 0.01) with losartan in the incubation bath. Losartan had no effect on
PGE
(2)-mediated
substance P
release in sham-CHF rats. In conclusion, the responsiveness of renal mechanosensory nerves is impaired in CHF rats due to ANG II inhibiting
PGE
(2)-mediated release of
substance P
from renal pelvic nerves.
...
PMID:Impaired responsiveness of renal mechanosensory nerves in heart failure: role of endogenous angiotensin. 1238 53
Several prostaglandin analogues used for glaucoma treatment cause increased pigmentation of the iris. The purpose of the present study was investigate whether latanoprost, a PGF(2 alpha) analogue, has any effect on the production of endogenous prostaglandins in iridial melanocytes, which could be important in the mechanism leading to increased pigmentation. Bovine and human iridial melanocytes in culture were used for the experiments. Production of endogenous prostaglandins was measured by enzyme immunoassay, and the melanin content was measured spectrophotometrically. In bovine iridial melanocytes, latanoprost acid caused a significant increase of the
PGE
(2) production, which could be blocked by indomethacin and NS398, indicating an involvement of cyclo-oxygenase 2. In order to study the selectivity of the phenomenon other endogenous substances/drugs were tested, e.g., acetylcholine, carbachol, noradrenaline, neuropeptide Y,
substance P
and alpha-MSH, but none was found to have any significant effect. Human iridial melanocytes also responded to latanoprost acid with increased production of
PGE
(2) and in 1 out of 5 individuals increased melanogenesis coincided with increased
PGE
(2) production. In bovine iridial melanocytes, latanoprost acid did not stimulate melanogenesis. These results indicate that latanoprost acid cause enhanced formation of endogenous prostaglandins that may have auto- and/or paracrine effects in the melanocytes, possibly associated with melanogenesis.
...
PMID:Production of prostaglandin e(2) by iridial melanocytes exposed to latanoprost acid, a prostaglandin F(2 alpha) analogue. 1241 90
(1) Peripheral inflammation causes an increase in the proportion of primary afferent neurones that express neurokinin(1) (NK(1)) receptors for
substance P
(SP). This upregulation may contribute to the neuronal mechanisms of inflammatory pain. The aim of this study was to identify endogenous mediators that stimulate upregulation of NK(1) receptors in dorsal root ganglion (DRG) neurones. Cultured DRG neurones from the adult normal rat were exposed for 2 days to media that contained specific mediators, namely potassium in high concentration, prostaglandin E(2) (
PGE
(2)), somatostatin (SRIF), and compounds influencing second messenger cascades. After fixation neurones were labelled with an NK(1) receptor antibody. (2) Repetitive addition of the inflammatory mediator
PGE
(2) or dibutyryl-cyclic adenosine 3',5' monophophate (db-cAMP) to the culture medium enhanced the proportion of neurones with NK(1) receptor-like immunoreactivity from about 12% up to 40%.
PGE
(2)-induced upregulation was prevented by coadministration of
PGE
(2) and a protein kinase A inhibitor or SRIF to the medium. High potassium concentration, protein kinase C inhibitors and omission of nerve growth factor from the medium had no effect. (3) In calcium-imaging experiments, bath application of SP evoked increases of the intracellular calcium concentration in about 20% of the neurones. This proportion increased to about 40% after
PGE
(2)-pretreatment, but the increase was prevented when
PGE
(2) and SRIF were coadministered to the medium. (4) These data show that the expression of NK(1) receptor-like immunoreactivity in DRG neurones is regulated by the inflammatory mediator
PGE
(2). This upregulation depends on the intracellular adenylyl cyclase-protein kinase A pathway.
...
PMID:Prostaglandin E2 increases the expression of the neurokinin1 receptor in adult sensory neurones in culture: a novel role of prostaglandins. 1278 27
Substance P
is a ubiquitous CNS neuropeptide and has recently been demonstrated to augment immune cell function during inflammatory events. Central to the ability of
substance P
to modulate immune cell function is the interaction of
substance P
with the
substance P
neurokinin-1 receptor expressed by a variety of immune cells, including microglia. CNS involvement during Lyme disease can occur when Borrelia burgdorferi, the causative agent of Lyme disease, gains access to the CNS. In the present study, we demonstrate that
substance P
augments B. burgdorferi-induced expression of mRNA encoding COX-2 and subsequent secretion of
PGE
(2) by cultured, murine microglia. Furthermore, this effect is associated with the ability of
substance P
to enhance B. burgdorferi-induced NF-kappa B activation, as demonstrated by increased nuclear localization of the p65 (RelA) subunit of NF-kappa B in these cells. Interestingly, we demonstrate that
substance P
augments B. burgdorferi-induced expression of mRNA encoding two
PGE
(2) receptors, E-prostanoid receptor subtypes 2 and 4, as well as each receptor protein. In addition, these effects are mediated via interactions between
substance P
and its high affinity receptor, as evidenced by the absence of augmented
PGE
(2) synthesis in the presence of a specific neurokinin-1 receptor antagonist or in cells genetically deficient in the expression of these receptors. Taken together, the present demonstration that
substance P
can exacerbate B. burgdorferi-induced inflammatory responses in microglia in vitro may indicate a role for this neuropeptide in the development of CNS inflammation observed during human neuroborreliosis.
...
PMID:Substance P augments Borrelia burgdorferi-induced prostaglandin E2 production by murine microglia. 1510 Mar 16
Induction of cyclooxygenase-2 (COX-2) in the renal pelvic wall increases prostaglandin E(2) (
PGE
(2)) leading to stimulation of cAMP production, which results in
substance P
(SP) release and activation of renal mechanosensory nerves. The subtype of
PGE
receptors involved, EP2 and/or EP4, was studied by immunohistochemistry and renal pelvic administration of agonists and antagonists of EP2 and EP4 receptors. EP4 receptor-like immunoreactivity (LI) was colocalized with calcitonin gene-related peptide (CGRP)-LI in dorsal root ganglia (DRGs) at Th(9)-L(1) and in nerve terminals in the renal pelvic wall. Th(9)-L(1) DRG neurons also contained EP3 receptor-LI and COX-2-LI, each of which was colocalized with CGRP-LI in some neurons. No renal pelvic nerves contained EP3 receptor-LI and only very few nerves COX-2-LI. The EP1/EP2 receptor antagonist AH-6809 (20 microM) had no effect on SP release produced by
PGE
(2) (0.14 microM) from an isolated rat renal pelvic wall preparation. However, the EP4 receptor antagonist L-161,982 (10 microM) blocked the SP release produced by the EP2/EP4 receptor agonist butaprost (10 microM) 12 +/- 2 vs. 2 +/- 1 and
PGE
(2), 9 +/- 1 vs. 1 +/- 0 pg/min. The SP release by butaprost and
PGE
(2) was similarly blocked by the EP4 receptor antagonist AH-23848 (30 microM). In anesthetized rats, the afferent renal nerve activity (ARNA) responses to butaprost 700 +/- 100 and
PGE
(2).780 +/- 100%.s (area under the curve of ARNA vs. time) were unaffected by renal pelvic perfusion with AH-6809. However, 1 microM L-161,982 and 10 microM AH-23848 blocked the ARNA responses to butaprost by 94 +/- 5 and 78 +/- 10%, respectively, and to
PGE
(2) by 74 +/- 16 and 74 +/- 11%, respectively. L-161,982 also blocked the ARNA response to increasing renal pelvic pressure 10 mmHg, 85 +/- 5%. In conclusion,
PGE
(2) increases renal pelvic release of SP and ARNA by activating EP4 receptors on renal sensory nerve fibers.
...
PMID:Activation of EP4 receptors contributes to prostaglandin E2-mediated stimulation of renal sensory nerves. 1529 51
1. Chronic inflammation is a central feature of asthma. The inflammatory cytokine tumour necrosis factor alpha (TNFalpha) has been implicated in this disease, and is known to alter airway smooth muscle functionally. 2. The aim of this study was to investigate the influence of TNFalpha on
tachykinin
-induced airway relaxation. Mouse tracheae were cultured in the absence and presence of TNFalpha for 1 or 4 days. 3. In the absence of TNFalpha,
substance P
(SP) and
neurokinin A
(
NKA
) induced comparable levels of relaxation in fresh and cultured segments. Functional studies with selective antagonists/inhibitors indicated that the relaxation was mediated by the NK(1) receptor coupled to cyclooxygenase (COX)-2 activation and subsequent release of prostaglandin E(2) (
PGE
(2)). TNFalpha attenuated SP- and
NKA
-induced relaxation in a time- and concentration-dependent manner, decreasing the ability of
PGE
(2) to relax tissues. 4. Further studies indicated that TNFalpha elevated COX-2 activity and that concomitant inhibition of COX-2 reversed TNFalpha-attenuated
PGE
(2) relaxation. Culture with
PGE
(2) decreased SP- and
PGE
(2)-mediated relaxation, further implicating the activity of COX-2 in the attenuation of
tachykinin
signalling. 5. Gene expression analysis demonstrated that TNFalpha increased the expression of smooth muscle COX-2,
PGE
(2) synthase and EP(2) receptor mRNA, and decreased the expression of the EP(4) receptor. 6. Overall, these results show that NK(1) receptor-mediated relaxation induced by
PGE
(2) is attenuated by prolonged TNFalpha stimulation. Increased COX-2 activity induced by TNFalpha appears to be central to this process.
...
PMID:TNF alpha reduces tachykinin, PGE2-dependent, relaxation of the cultured mouse trachea by increasing the activity of COX-2. 1566 61
Galanin by a spinal action has been shown to have an antihyperalgesic action. Thus, in rats with lumbar intrathecal (IT) catheters, the thermal hyperalgesia evoked by carrageenan paw injection was blocked by IT delivery of galanin(1-29) (Gal(1-29)) and galanin(2-11) (Gal(2-11)) with the rank order of activity being Gal(1-29)>Gal(2-11). We sought to determine whether this spinal action reflects an effect upon afferent transmitter release, e.g.,
substance P
(SP), and/or on secondary neurons, e.g., signaling postsynaptic to
neurokinin 1
(
NK1
) receptor activation. To address the question on afferent release, we investigated the effect of IT administration of galanin on tissue injury-induced spinal
NK1
internalization (an indicator of SP release). Noxious stimulation (paw compression) produced an increase in
NK1
internalization in dorsal horn lamina I. IT pretreatment of rats with Gal(1-29) and Gal(2-11) significantly attenuated the evoked
NK1
internalization, with the rank order of activity being Gal(1-29)>Gal(2-11)>saline. To address the question of postsynaptic action, we examined the effects of IT galanin upon IT SP-induced thermal hyperalgesia and spinal PGE2 release. Application of SP (30 nmol) directly to spinal cord led to a decrease in thermal thresholds and a profound increase in
PGE
(2) concentration in spinal dialysates. Both phenomena were reversed by Gal(1-29) and Gal(2-11) (10nmol, IT). These findings suggest that the antihyperalgesic effect of spinal galanin is due to its action on sites both presynaptic (inhibition of SP release) and postsynaptic (blockade of SP-evoked hyperalgesia and PGE2 production) to the primary afferents.
...
PMID:Mechanisms of antinociception of spinal galanin: how does galanin inhibit spinal sensitization? 1594 14
Recent studies on prostanoids showed that some of prostanoid receptors are expressed in rat dorsal root ganglion (DRG) neurons. These facts suggest that prostanoid receptors might be involved in the excitation mechanism of DRG neurons. In the present study, PCR experiments revealed that one of prostanoid receptor, prostacyclin receptor (IP receptor) was expressed in L6 and S1 rat DRG neurons and that the expression of IP receptor was not changed in DRG neurons obtained from the cyclophosphamide (CYP)-induced cystitis rat. We examined the functional role of IP receptor agonist and other prostanoids by measuring cyclic AMP (cAMP) accumulation and
substance P
(SP) release in primary cultured DRG neurons. The pretreatment of DRG neurons with prostanoid agonists such as iloprost (IP), butaprost (EP(2)), misoprostol (EP(2-4)),
PGE
(2) (EP(1-4)) or PGD(2) (DP and CRTH2) sensitized the DRG neurons and hence potentiated the lys-bradykinin-induced SP release. The increase of SP release by lys-BK plus prostanoid agonists was proportion to cAMP accumulation. Iloprost was the most potent agonist to induce cAMP accumulation and SP release among prostanoid agonists evaluated in this study and its effect is mediated by IP receptor. Moreover, capsaicin-, ATP- and KCl-induced SP release was also enhanced by iloprost although iloprost did not change intracellular Ca(2+) and membrane depolarization induced by these chemical stimuli. These results strongly indicate that IP receptor play an important role in the sensitization of rat sensory neuron.
...
PMID:Functional role of prostacyclin receptor in rat dorsal root ganglion neurons. 1603 53
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