prostaglandin-d2 and Pain

Pain is a multidimensional experience involving the biological, psychological, and social dimensions of each individual. Particularly, the biological aspects of pain conditions are a response of the neuroimmunology system and the control of painful conditions is a worldwide challenge for researchers. Although years of investigation on pain experience and treatment exist, the high prevalence of chronic pain is still a fact.. Peroxisome proliferator-activated receptor-gamma (PPARγ) is a ligand-activated transcription factor belonging to the nuclear hormone receptor superfamily. It regulates several metabolic pathways, including lipid biosynthesis and glucose metabolism, when activated. However, PPARγ activation also has a critical immunomodulatory and neuroprotective effect.. This review summarizes the evidence of synthetic or natural PPARγ ligands such as 15d-PGJ

Topics: Humans; Immunomodulation; Ligands; Pain; PPAR gamma; Prostaglandin D2; Thiazolidinediones

Fetal pain and fetal anesthesia are still matter of debate: some authors hypothesize that several intrauterine endocrine neuroinhibitors (ENIn) anesthetize the fetus, keeping it in a constant state of sleep, and making pharmacological fetal anesthesia useless for fetal surgery, while others argue fetal pain is possible and shoud be prevented with fetal anesthesy.. To retrieve evidences about fetal pain, fetal arousability and about the level of sedation induced by the ENIn, in order to assess the necessity of direct fetal anesthesia during prenatal fetal surgery.. We performed a careful literature review (1990-2016) on fetal arousability, and on the possibility that ENIn at the average fetal blood levels induce actual anesthesia. We retrieved the papers that fulfilled the research criteria, with particular attention to the second half of pregnancy, the period when most fetal surgery is performed.. Fetuses are awake about 10% of the total time in the last gestational weeks, and they can be aroused by external stimuli. ENIn have not an anesthetic effect at normal fetal values, but only when they areartificialy injected at high doses; their blood levels in the last trimester of average pregnancies are not dissimilar either in the fetus or in the mother.. During the second half of the pregnancy, external stimuli can awake the fetuses, although they spend most of the time in sleeping state; the presence of ENIn is absolutely not enough to guarantee an effective anesthesia during surgery. Thus, direct fetal analgesia/anesthesia is mandatory, though further studies on its possible drawbacks are necessary.

Topics: Adenosine; Analgesia; Anesthesia; Arousal; Female; Fetal Blood; Fetus; Gestational Age; Humans; MEDLINE; Nervous System; Pain; Pain Management; Pregnancy; Pregnanolone; Prostaglandin D2

Topics: Amyloid beta-Peptides; Animals; Crystallography, X-Ray; Drug Design; Humans; Hypersensitivity; Inflammation; Intramolecular Oxidoreductases; Lipocalins; Molecular Chaperones; Muscular Dystrophies; Pain; Piperidines; Prostaglandin D2; Protein Conformation; Sleep

Inflammation of the urinary bladder may cause burdensome pain also called bladder pain syndrome (BPS). A limitation in understanding BPS pathophysiology is the lack of appropriate preclinical model. Previously published clinical and preclinical studies revealed positive impact of Cernitin™ on pain relief in chronic prostatitis. The objective of this study was to evaluate the effects of Cernitin™ on induced inflammation of the urinary bladder in rats. We also sought to identify biomarkers which might play a role in the management of BPS.. Cystitis was induced by injection of cyclophosphamide (CYP) in female rats. Thereafter, animals were randomly divided into four treatment groups and two control groups. Evaluation of pain scores was assessed by von Frey assay. Expression of pain- and pro-inflammatory biomarkers was determined by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry.. Treatments with Cernitin™ displayed significant anti-nociceptive effects on CYP-induced visceral pain (. Cernitin™ components reduced pain score and inflammatory marker COX-2. Our findings suggest a potential therapeutic role for Cernitin™ in the management of BPS.

Topics: Animals; Biomarkers; Cyclooxygenase 2; Cyclophosphamide; Cystitis; Female; Male; Pain; Prostaglandin D2; Rats

Sleep disturbances, pain, and inflammation co-occur in various medical conditions, but their interrelationships are poorly understood.. We investigated the effects of reduced sleep duration (by approximately 50%) to 4 h/night across 10 days, on peripherally circulating inflammatory mediators. In addition, we tested the prediction that degree of inflammation is quantitatively related to the extent to which pain is increased in response to prolonged sleep restriction.. Randomized, 16 day controlled in-laboratory study conducted in GCRC.. Eighteen volunteers were randomly assigned to either 12 days of sleeping 8 h/night or 4 h/night. Participants rated mood and pain symptoms throughout experimental days. Urine was collected and blood was drawn frequently on the baseline day and after the 10th experimental day for 25 hours.. Levels of plasma interleukin (IL)-6, serum C-reactive protein (CRP), plasma soluble tumor necrosis factor receptor p55 (sTNF-R p55), urinary levels of prostaglandin (PG) metabolites D2 and E2, subjective assessment of pain and tiredness-fatigue.. IL-6 levels were elevated in the 4-h sleep condition over the 8-h sleep condition (P <0.05). CRP levels showed the same trend as IL-6, but did not differ significantly between groups (P = 0.11). Levels of sTNF-R p55 were unchanged in both groups. PG E2 and 11beta-F2alpha metabolite increased in 4-h sleepers, but did not differ significantly from the 8-h sleepers. Elevated IL-6 levels were strongly associated with increased pain ratings in response to sleep restriction (r = 0.67, P <0.01), and this association could not be explained by elevations in tiredness-fatigue.. Insufficient sleep quantity may facilitate and/or exacerbate pain through elevations of IL-6. In disorders where sleep disturbances are common, insufficient sleep quantity itself may establish and maintain its co-occurrence with pain and increased inflammation.

Topics: Adult; Biomarkers; C-Reactive Protein; Dinoprostone; Female; Health Status; Humans; Inflammation; Interleukin-6; Male; Pain; Pain Measurement; Prostaglandin D2; Receptors, Tumor Necrosis Factor, Type I; Reference Values; Sleep Deprivation; Tumor Necrosis Factor Decoy Receptors

To overcome negative adverse effects and improve therapeutic index of dexamethasone (Dex) in rheumatoid arthritis (RA), we developed a novel sustained release formulation-intra-articular injectable dexamethasone-loaded thermosensitive hydrogel (DLTH) with chitosan-glycerin-borax as carrier for the remission of inflammation and pain. The focus of this article is to explore both anti-inflammatory and pain-relieving effects of DLTH joint injection in bovine type-II collagen-induced arthritis (CIA) rats.. Wistar rats were randomized into three groups, including the normal group (n=6), the model group (n=6) and the DLTH group (n=10). Joint injection of DLTH (1mg/kg Dex per rat) was injected on day 12 in the DLTH group twice a week for three weeks. Clinical signs of body weight, paw swelling and arthritis scores, histologic analysis, hind paw mechanical withdrawal threshold (MWT), plantar pressure pain threshold (PPT) were taken into consideration. Serum contents of IL-17A, prostaglandin E2 (PGE2), prostacyclin 2 (PGI2) and prostaglandin D2 (PGD2), real-time polymerase chain reaction (PCR) analysis of inflammatory factors and pain-related mediators in synovium and dorsal root ganglia (DRG), Western blotting of NF-κB in synovium were all evaluated.. Paw swelling, arthritis scores and joint inflammation destruction were all attenuated in the DLTH-treated group. Results showed that DLTH not only down-regulated serum IL-17A, but also mRNA levels of inflammatory factors and NGF, and key proteins contents of the NF-κB pathway in synovium. Increases of MWT and PPT in DLTH-treated rats elucidated pain-reducing effects of DLTH. Elevated serum PGD2 levels and declines of serum PGE2 and PGI2, and inflammatory and pain-related genes in DRGs in the DLTH group were also recorded.. These data elucidated that DLTH joint injection impeded synovial inflammation processes through down-regulating transcription activity of NF-κB pathway, and intra-articular DLTH may aid in the regulation of RA pain through regulating inflammation and pain conduction process.

Topics: Animals; Anti-Inflammatory Agents; Arthritis, Experimental; Body Weight; Dexamethasone; Dinoprostone; Edema; Ganglia, Spinal; Hydrogels; Inflammation; Interleukin-17; Male; NF-kappa B; Pain; Pain Threshold; Prostaglandin D2; Rats; Rats, Wistar; Synovial Membrane

Gout arthritis (GA) is a painful inflammatory disease in response to monosodium urate (MSU) crystals in the joints. 15deoxy-Δ

Topics: Animals; Antioxidants; Arthritis, Experimental; Arthritis, Gouty; Inflammation; Male; Mice; Mice, Inbred C57BL; Nanocapsules; Oxidative Stress; Pain; PPAR gamma; Prostaglandin D2; Uric Acid

The pain arising from temporomandibular disorders is often treated with opioids and agents that inhibit the immune response and are associated with substantial adverse effects and long-term risks. Thus, the development of new therapies that are safer and more effective is of great interest to patients and clinicians. 15-deoxy-Δ

Topics: Administration, Cutaneous; Animals; Anti-Inflammatory Agents; Cytokines; Drug Delivery Systems; Excipients; Hyaluronic Acid; Injections, Intra-Articular; Microinjections; Needles; Nociception; Pain; Permeability; Prostaglandin D2; Rats, Wistar; Skin; Temporomandibular Joint; Temporomandibular Joint Disorders; Tissue Distribution

Prostaglandins (PGs), particularly prostaglandin D. Rat closed-cranial window (CCW) model was used to study the effect of the DP. PGD. High expression of DP

Topics: Animals; Brain; Dose-Response Relationship, Drug; Female; Intramolecular Oxidoreductases; Lipocalins; Meningeal Arteries; Pain; Prostaglandin D2; Rats; Rats, Sprague-Dawley; Receptors, Prostaglandin; RNA, Messenger; Transcriptome; Trigeminal Nuclei; Vasodilation

Normal and painful stimuli are detected by specialized subgroups of peripheral sensory neurons. The understanding of the functional differences of each neuronal subgroup would be strongly enhanced by knowledge of the respective subgroup transcriptome. The separation of the subgroup of interest, however, has proven challenging as they can hardly be enriched. Instead of enriching, we now rapidly eliminated the subgroup of neurons expressing the heat-gated cation channel TRPV1 from dissociated rat sensory ganglia. Elimination was accomplished by brief treatment with TRPV1 agonists followed by the removal of compromised TRPV1(+) neurons using density centrifugation. By differential microarray and sequencing (RNA-Seq) based expression profiling we compared the transcriptome of all cells within sensory ganglia versus the same cells lacking TRPV1 expressing neurons, which revealed 240 differentially expressed genes (adj. p<0.05, fold-change>1.5). Corroborating the specificity of the approach, many of these genes have been reported to be involved in noxious heat or pain sensitization. Beyond the expected enrichment of ion channels, we found the TRPV1 transcriptome to be enriched for GPCRs and other signaling proteins involved in adenosine, calcium, and phosphatidylinositol signaling. Quantitative population analysis using a recent High Content Screening (HCS) microscopy approach identified substantial heterogeneity of expressed target proteins even within TRPV1-positive neurons. Signaling components defined distinct further subgroups within the population of TRPV1-positive neurons. Analysis of one such signaling system showed that the pain sensitizing prostaglandin PGD2 activates DP1 receptors expressed predominantly on TRPV1(+) neurons. In contrast, we found the PGD2 producing prostaglandin D synthase to be expressed exclusively in myelinated large-diameter neurons lacking TRPV1, which suggests a novel paracrine neuron-neuron communication. Thus, subgroup analysis based on the elimination rather than enrichment of the subgroup of interest revealed proteins that define subclasses of TRPV1-positive neurons and suggests a novel paracrine circuit.

Topics: Animals; Base Sequence; Capsaicin; Cells, Cultured; Ganglia, Spinal; Gene Expression Profiling; Male; Nociceptors; Pain; Paracrine Communication; Phosphatidylinositols; Potassium Channels; Prostaglandin D2; Rats; Rats, Sprague-Dawley; Receptors, G-Protein-Coupled; Sequence Analysis, DNA; TRPV Cation Channels

Systemic administration of thiazolidinediones reduces peripheral inflammation in vivo, presumably by acting at peroxisome proliferator-activated receptor gamma (PPARgamma) in peripheral tissues. Based on a rapidly growing body of literature indicating the CNS as a functional target of PPARgamma actions, we postulated that brain PPARgamma modulates peripheral edema and the processing of inflammatory pain signals in the dorsal horn of the spinal cord. To test this in the plantar carrageenan model of inflammatory pain, we measured paw edema, heat hyperalgesia, and dorsal horn expression of the immediate-early gene c-fos after intracerebroventricular (ICV) administration of PPARgamma ligands or vehicle. We found that ICV rosiglitazone (0.5-50 microg) or 15d-PGJ(2) (50-200 microg), but not vehicle, dose-dependently reduced paw thickness, paw volume and behavioral withdrawal responses to noxious heat. These anti-inflammatory and anti-hyperalgesia effects result from direct actions in the brain and not diffusion to other sites, because intraperitoneal and intrathecal administration of rosiglitazone (50 microg) and 15d-PGJ(2) (200 microg) had no effect. PPARgamma agonists changed neither overt behavior nor motor coordination, indicating that non-specific behavioral effects do not contribute to PPAR ligand-induced anti-hyperalgesia. ICV administration of structurally dissimilar PPARgamma antagonists (either GW9662 or BADGE) reversed the anti-inflammatory and anti-hyperalgesic actions of both rosiglitazone and 15d-PGJ(2). To evaluate the effects of PPARgamma agonists on a classic marker of noxious stimulus-evoked gene expression, we quantified Fos protein expression in the dorsal horn. The number of carrageenan-induced Fos-like immunoreactive profiles was less in rosiglitazone-treated rats as compared to vehicle controls. We conclude that pharmacological activation of PPARgamma in the brain rapidly inhibits local edema and the spinal transmission of noxious inflammatory signals.

Topics: Anilides; Animals; Benzhydryl Compounds; Brain; Central Nervous System Agents; Disease Models, Animal; Edema; Epoxy Compounds; Gene Expression; Inflammation; Male; Pain; PPAR gamma; Prostaglandin D2; Proto-Oncogene Proteins c-fos; Rats; Rats, Sprague-Dawley; Rosiglitazone; Spinal Cord; Thiazolidinediones

This study assessed the effect of the agonist 15d-PGJ(2) administered into the rat temporomandibular joint (TMJ) on nociceptive behavioral and the anti-inflammatory potential of this prostaglandin on TMJ. It was observed that 15-deoxy-(Delta12,14)-prostaglandin J(2) (15d-PGJ(2)) significantly reduced formalin-induced nociceptive behavior in a dose dependent manner, however injection of 15d-PGJ(2) into the contralateral TMJ failed to reduce such effects. This antinociceptive effect is dependent on peroxisome proliferator-activated receptors-gamma (PPAR-gamma) since pre-treatment with GW9662 (PPAR-gamma receptor antagonist) blocked the antinociceptive effect of 15d-PGJ(2) in the TMJ. In addition, the antinociceptive effect of 15d-PGJ(2) was also blocked by naloxone suggesting the involvement of peripheral opioids in the process. Confirming this hypothesis pre-treatment with kappa, delta, but not mu receptor antagonists significantly reduced the antinociceptive effect of 15d-PGJ(2) in the TMJ. Similarly to opioid agonists, the 15d-PGJ(2) antinociceptive action depends on the nitric oxide (NO)/guanilate cyclase (cGMP)/ATP-sensitive potassium channel blocker(K(+)(ATP)) channel pathway since it was prevented by the pre-treatment with the inhibitors of nitric oxide synthase (NOS; aminoguanidine), cGMP (ODQ), or the K(+)(ATP) (glibenclamide). In addition, 15d-PGJ(2) (100 ng/TMJ) inhibits 5-HT-induced TMJ hypernociception. Besides, TMJ treated with 15d-PGJ(2) showed lower vascular permeability, assessed by Evan's Blue extravasation, and also lower neutrophil migration induced by carrageenan administration. Taken together, these results demonstrate that 15d-PGJ(2) has a potential peripheral antinociceptive and anti-inflammatory effect in the TMJ via PPAR-gamma activation. The results also suggest that 15d-PGJ(2) induced-peripheral antinociceptive response in the TMJ is mediated by kappa/delta opioid receptors by the activation of the intracellular l-arginine/NO/cGMP/K(+)(ATP) channel pathway. The pharmacological properties of the peripheral administration of 15d-PGJ(2) highlight the potential use of this PPAR-gamma agonist on TMJ inflammatory pain conditions.

Topics: Analgesics; Animals; Cyclic GMP; Dose-Response Relationship, Drug; Formaldehyde; Inflammation; KATP Channels; Male; Nitric Oxide Synthase; Pain; PPAR gamma; Prostaglandin D2; Rats; Rats, Wistar; Receptors, Opioid, delta; Receptors, Opioid, kappa; Receptors, Opioid, mu; Serotonin; Signal Transduction; Temporomandibular Joint

The 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)) is an endogenous ligand of peroxisome proliferator-activated receptors gamma (PPAR-gamma) and is now recognized as a potent anti-inflammatory mediator. However, information regarding the influence of 15d-PGJ(2) on inflammatory pain is still unknown. In this study, we evaluated the effect of 15d-PGJ(2) upon inflammatory hypernociception and the mechanisms involved in this effect. We observed that intraplantar administration of 15d-PGJ(2) (30-300 ng/paw) inhibits the mechanical hypernociception induced by both carrageenan (100 mug/paw) and the directly acting hypernociceptive mediator, prostaglandin E(2) (PGE(2)). Moreover, 15d-PGJ(2) [100 ng/temporomandibular joint (TMJ)] inhibits formalin-induced TMJ hypernociception. On the other hand, the direct administration of 15d-PGJ(2) into the dorsal root ganglion was ineffective in blocking PGE(2)-induced hypernociception. In addition, the 15d-PGJ(2) antinociceptive effect was enhanced by the increase of macrophage population in paw tissue due to local injection of thioglycollate, suggesting the involvement of these cells on the 15d-PGJ(2)-antinociceptive effect. Moreover, the antinociceptive effect of 15d-PGJ(2) was also blocked by naloxone and by the PPAR-gamma antagonist 2-chloro-5-nitro-N-phenylbenzamide (GW9662), suggesting the involvement of peripheral opioids and PPAR-gamma receptor in the process. Similar to opioids, the 15d-PGJ(2) antinociceptive action depends on the nitric oxide/cGMP/protein kinase G (PKG)/K(ATP)(+) channel pathway because it was prevented by the pretreatment with the inhibitors of nitric-oxide synthase (N(G)-monomethyl-l-arginine acetate), guanylate cyclase]1H-(1,2,4)-oxadiazolo(4,2-alpha)quinoxalin-1-one[, PKG [indolo[2,3-a]pyrrolo[3,4-c]carbazole aglycone (KT5823)], or with the ATP-sensitive potassium channel blocker glibenclamide. Taken together, these results demonstrate for the first time that 15d-PGJ(2) inhibits inflammatory hypernociception via PPAR-gamma activation. This effect seems to be dependent on endogenous opioids and local macrophages.

Topics: Analgesics; Animals; Carrageenan; Cytokines; Formaldehyde; Hyperalgesia; Inflammation; Macrophages; Male; Naloxone; Narcotic Antagonists; Pain; PPAR gamma; Prostaglandin D2; Rats; Rats, Wistar; Receptors, Opioid; Skin; Tumor Necrosis Factor-alpha

Synurus deltoides was previously found to possess significant anti-inflammatory activity especially against chronic inflammation, and strong analgesic activity in vivo. In this study, new anti-inflammatory formulation containing S. deltoides extract as a major ingredient was prepared and in vivo activity was evaluated. The plausible action mechanism was also investigated. The new formulation (SAG) contains 1 part of S. deltoides extract, 0.9 part of Angelica gigas extract and 0.9 part of glucosamine sulfate (w/w). SAG inhibited dose-dependently edematic response of arachidonic acid (AA)- and 12-O-tetradecanoyl 13-acetate (TPA)-induced ear edema in mice, which is an animal model of acute inflammation. SAG showed 44.1% inhibition of AA-induced ear edema at an oral dose of 50 mg/kg. In an animal model of chronic inflammation, SAG clearly reduced the edematic response of 7-day model of multiple treatment of TPA (38.1% inhibition at 200 mg/kg/day). Furthermore, SAG (50-800 mg/kg/day) as well as S. deltoides extract (285 mg/kg/day) significantly inhibited prostaglandin E2 production from the skin lesion of the animals of 7-day model. These results were well correlated with in vitro finding that SAG as well as S. deltoides extract reduced cyclooxygenase (COX)-1- and COX-2-induced prostanoid production, measured in mouse bone marrow-derived mast cells. Therefore, these results suggest that SAG possesses anti-inflammatory activity in vivo against acute as well as chronic inflammatory animal models at least in part by inhibition of prostaglandin production through COX-1/COX-2 inhibition. And COX inhibition of SAG is possibly contributed by S. deltoides extract among the ingredients. Although the anti-inflammatory potencies of SAG were less than those of currently used anti-inflammatory drugs, this formulation may have beneficial effect on inflammatory disorders as a neutraceutical.

Topics: Acetic Acid; Angelica; Animals; Anti-Inflammatory Agents, Non-Steroidal; Arachidonic Acid; Asteraceae; Bone Marrow Cells; Cells, Cultured; Dose-Response Relationship, Drug; Drug Combinations; Edema; Glucosamine; Male; Mice; Mice, Inbred BALB C; Mice, Inbred ICR; Pain; Plant Extracts; Prostaglandin D2; Tetradecanoylphorbol Acetate

Prostaglandin (PG) D2 is the most abundant prostanoid produced in the central nervous system of mammals and has been implicated in the modulation of neural functions such as sleep induction, nociception, regulation of body temperature, and odor responses. We generated gene-knockout mice for lipocalin-type PGD2 synthase (L-PGDS) and found that the intrathecal administration of PGE2, an endogenous pain-producing substance, failed to elicit allodynia (touch-evoked pain), which is one typical phenomenon of neuropathic pain, whereas it evoked thermal hyperalgesia, in L-PGDS-/- mice. We also found that the allodynic response induced by the gamma-aminobutyric acid (GABA)A receptor antagonist bicuculline was selectively abolished in the L-PGDS-/- mice, among excitatory and inhibitory agents that induced allodynia in wild-type mice. Interestingly, simultaneous injection of a femtogram amount of PGD2 with PGE2 or bicuculline induced allodynia in L-PGDS-/- mice to the same extent as in wild-type mice. The PGE2- or bicuculline-evoked allodynia in wild-type and in PGD2-supplemented L-PGDS-/- mice was blocked by a PGD2 receptor antagonist given in a femtogram amount. These results reveal that endogenous PGD2 is essential for both PGE2- and bicuculline-induced allodynia.

Topics: Anesthesia; Animals; Bicuculline; Central Nervous System; Dinoprost; Dinoprostone; GABA Antagonists; Gene Targeting; Hydantoins; Hyperalgesia; Immunohistochemistry; Intramolecular Oxidoreductases; Lipocalins; Mice; Mice, Knockout; Molecular Sequence Data; Pain; Prostaglandin D2; Receptors, Prostaglandin

1. We recently showed that intrathecal administration of nociceptin induced allodynia by innocuous tactile stimuli and hyperalgesia by noxious thermal stimuli in conscious mice. In the present study, we examined the effect of prostaglandins on nociceptin-induced allodynia and hyperalgesia. 2. Prostaglandin D2 (PGD2) blocked the allodynia induced by nociceptin in a dose-dependent manner with an IC50 of 26 ng kg(-1), but did not affect the nociceptin-induced hyperalgesia at doses up to 500 ng kg(-1). BW 245C (an agonist for PGD (DP) receptor) blocked the allodynia with an IC50 of 83 ng kg(-1). 3. The blockade of nociceptin-induced allodynia by PGD2 was reversed by the potent and selective DP-receptor antagonist BW A868C in a dose-dependent manner with an ED50 of 42.8 ng kg(-1). 4. Glycine (500 ng kg[-1]) almost completely blocked the nociceptin-induced allodynia. A synergistic effect on the inhibition of nociceptin-evoked allodynia was observed between glycine and PGD2 at below effective doses. 5. Dibutyryl cyclic AMP, but not dibutyryl cyclic GMP, blocked the nociceptin-induced allodynia with an IC50 of 2.9 microg kg(-1). 6. PGE2, PGF2alpha, butaprost (an EP2 agonist) and cicaprost (a PGI receptor agonist) did not affect the nociceptin-induced allodynia. 7. These results demonstrate that PGD2 inhibits the nociceptin-evoked allodynia through DP receptors in the spinal cord and that glycine may be involved in this inhibition.

Topics: Animals; Bucladesine; Dibutyryl Cyclic GMP; Glycine; Hyperalgesia; Male; Mice; Narcotic Antagonists; Nociceptin; Opioid Peptides; Pain; Prostaglandin D2

We previously reported that intrathecal administration of prostaglandin (PG) D2 and PGE2 to conscious mice induced hyperalgesia (assessed by a hot-plate test) and that intrathecal administration of PGE2 and PGF2 alpha induced allodynia, a state of discomfort and pain evoked by innocuous tactile stimuli. In the present study, we examined the relationships of pain responses among PGD2, PGE2 and PGF2 alpha, PGF2 alpha additively augmented the allodynia evoked by a submaximal dose (1 ng/mouse) of PGE2. On the other hand, PGD2 dose-dependently blocked the allodynia induced by a maximal dose (10 ng/mouse) of PGE2, with an IC50 of 93.2 pg/mouse, but did not affect the PGE2 (10 ng)-induced hyperalgesia at doses up to 10 ng. BW 245C, an agonist for PGD2 receptors (DP receptors), but not another DP receptor agonist (ZK 110841) blocked the allodynia similarly. The blockade of PGE2-induced allodynia by 10 ng of PGD2 was reversed by the potent and selective DP receptor antagonist BW A868C, in a dose-dependent manner. Intrathecal administration of BW A868C induced allodynia by itself over a wide range, from 10 pg to 100 ng. and the allodynia induced by 100 ng of BW A868C was dose-dependently antagonized by PGD2. These results demonstrate that PGD2 blocked the PGE2-evoked allodynia through DP receptors in the spinal cord, and they imply that endogenous PGD2 may play an inhibitory role in the appearance of allodynia under physiological conditions.

Topics: Adrenergic Agonists; Animals; Dinoprost; Dinoprostone; Dose-Response Relationship, Drug; gamma-Aminobutyric Acid; Glycine; Hydantoins; Male; Mice; N-Methylaspartate; Pain; Prostaglandin D2; Spinal Cord; Wakefulness

We recently reported that intrathecal (i.t) administration of prostaglandin (PG) F2 alpha to conscious mice induced allodynia that was elicited by non-noxious brushing of the flanks. In the presents study, we demonstrate that i.t. administration of PGD2 and PGE2 to conscious mice also results in allodynia. Dose dependency of PGD2 for allodynia showed a skewed bell-shaped pattern (0.1 ng-2.5 micrograms/mouse), and the maximal allodynic effect was observed with 1.0 microgram at 15 min after intrathecal injection. PGD2-induced allodynia showed a time course and dose dependency similar to that induced by PGF2 alpha, but with lower scores. On the other hand, dose dependency of PGE2 for allodynia showed a bell-shaped pattern over a wide range of dosage from 10 fg to 2.0 micrograms/mouse. The maximal allodynic effect was observed with 0.01-0.1 microgram at 5 min after i.t. injection, and the response gradually decreased over the experimental period of 50 min. Intrathecally administered strychnine and the GABAA antagonist bicuculline also induced allodynia in conscious mice. The time courses of allodynia evoked by strychnine and bicuculline coincided with those by PGE2 and PGF2 alpha, respectively. PGE2-induced allodynia was dose-dependently relieved by the strychnine-sensitive glycine receptor agonist taurine, the NMDA receptor antagonist ketamine, and a high dose of the alpha 2-adrenergic agonist clonidine, but not by the GABAA agonist muscimol or by the GABAB agonist baclofen. In contrast, PGF2-induced allodynia was dramatically inhibited by clonidine and baclofen, but not by taurine, ketamine or muscimol.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Bicuculline; Dinoprostone; Excitatory Amino Acid Antagonists; Glutamates; Glutamic Acid; Hyperalgesia; Injections, Spinal; Male; Mice; Mice, Inbred Strains; Pain; Prostaglandin D2; Strychnine

Intracisternal administration of PGD2 (5 micrograms) and PGE2 (5 micrograms) induced hypoalgesia in conscious mice in acetic acid writhing test. The hypoalgesia caused by PGD2 was blocked by para-chlorophenylalanine, cyproheptadine or phenoxybenzamine. However, the suppression of writhing responses caused by PGE2 was not blocked at all by these drugs. These results indicate that the actions of PGD2 depend upon serotonin and norepinephrine systems.

Topics: Animals; Cisterna Magna; Dinoprostone; Male; Mice; Pain; Prostaglandin D2

The relative potencies of PGD2, PGE2 and PGI2 in potentiating bradykinin-induced hyperalgesia and oedema were determined in the paws of aspirin-treated guinea-pigs. PGE2 and to a lesser degree PGD2 but not PGI2, potentiated bradykinin-induced hyperalgesia, whereas PGD2, but not PGE2 or PGI2, potentiated oedema. These findings differ from those in other species, and possibly reflect interspecies differences in modulation of inflammatory reactions by prostanoids.

Topics: Animals; Aspirin; Bradykinin; Dinoprostone; Edema; Epoprostenol; Female; Guinea Pigs; Pain; Prostaglandin D2; Prostaglandins; Sensory Thresholds

Hyperalgesic actions in mice of intracerebroventricularly (i.c.v.) administered arachidonic acid, prostaglandin (PG) E2, PG F2 alpha and PG D2 were studied. For the analgesic assay, the mouse tail pressure method was employed. The i.c.v. administration of arachidonic acid (0.01-100 micrograms/mouse), PG E2 (0.01-100 ng/mouse), PG F2 alpha (0.1-1000 ng/mouse) and PG D2 (0.1-1000 ng/mouse) decreased the pain threshold in a dose dependent manner. The doses that produced the maximal decrease in pain threshold for arachidonic acid, PG E2, PG F2 alpha and PG D2 were 10 micrograms/mouse, 10 ng/mouse, 100 ng/mouse and 100 ng/mouse, respectively. Acidic nonsteroidal antiinflammatory drugs (NSAIDs) produced much more potent analgesic effects in arachidonic acid-induced hyperalgesic mice than in normal mice and in PG E2-, PG F2 alpha- and PG D2-induced hyperalgesic mice, but nonacidic NSAIDs and morphine produced the same analgesic effect in both hyperalgesic and normal mice. Linoleic acid, linolenic acid and gamma-linolenic acid induced weak hyperalgesia, but this unsaturated fatty acids-induced hyperalgesia was not affected by indomethacin (2 mg/kg, p.o.). These findings indicate that the arachidonic acid and its metabolites were related to mediation or modulation of central pain pathways and that the central nervous system may be partially involved in the action of acidic NSAIDs.

Topics: Analgesics; Animals; Anti-Inflammatory Agents, Non-Steroidal; Arachidonic Acid; Arachidonic Acids; Dinoprost; Dinoprostone; Fatty Acids, Unsaturated; Injections, Intraventricular; Male; Mice; Pain; Prostaglandin Antagonists; Prostaglandin D2; Prostaglandins; Prostaglandins D; Prostaglandins E; Prostaglandins F; Sensory Thresholds

The effect of intracisternal administration of three major prostaglandins on nociceptive responses was evaluated in mice. Prostaglandin D2 had biphasic effects on pain thresholds (hot plate and acetic acid writhing tests) when given in a dosage range of 5 ng to 5 micrograms per mouse. Lower doses of prostaglandin D2 (less than or equal to 15 ng) increased the sensitivity to pain stimulation. Higher doses (greater than or equal to 50 ng) caused hypoalgesia, which was completely blocked by intracisternal injection of 500 pg of naloxone. Prostaglandin E2 (5 ng-5 micrograms) also had a biphasic effect on pain thresholds, similar to the effect of prostaglandin D2. However, the hypoalgesia caused by a higher dose of prostaglandin E2 (5 micrograms) was not blocked at all by naloxone doses of up to 500 ng. Prostaglandin F2 alpha had little effect on pain thresholds. These results indicate that each prostaglandin has a specific effect on the modulation of nociception.

Topics: Animals; Cisterna Magna; Dinoprost; Dinoprostone; Injections; Male; Mice; Nociceptors; Pain; Prostaglandin D2; Prostaglandins; Prostaglandins D; Prostaglandins E; Prostaglandins F; Reaction Time; Time Factors

Topics: Acetylcholine; Alprostadil; Animals; Bradykinin; Dinoprostone; Inflammation; Injections, Intraventricular; Male; Mice; Pain; Prostaglandin D2; Prostaglandins; Prostaglandins D; Prostaglandins E; Rats; Rats, Inbred Strains; Sensory Thresholds