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OBJECTIVES: Research has demonstrated that chronic stress experienced early in life can lead to impairments in memory and learning. These deficits are attributed to an imbalance in the interaction between glucocorticoids, the end product of the hypothalamic-pituitary-adrenal (HPA) axis, and glucocorticoid receptors in brain regions responsible for mediating memory, such as the hippocampus. This imbalance can result in detrimental conditions like neuroinflammation. The aim of this study was to assess the impact of sumatriptan, a selective agonist for 5-HT 1B/1D receptors, on fear learning capabilities in a chronic social isolation stress model in mice, with a particular focus on the role of the HPA axis. METHODS: Mice were assigned to two opposing conditions, including social condition (SC) and isolated condition (IC) for a duration of five weeks. All mice underwent passive avoidance test, with their subsequent freezing behavior serving as an indicator of fear retrieval. Mice in the IC group were administered either a vehicle, sumatriptan, GR-127935 (a selective antagonist for 5-HT 1B/1D receptors), or a combination of sumatriptan and GR-127935 during the testing sessions. At the end, all mice were sacrificed and samples of their serum and hippocampus were collected for further analysis. RESULTS: Isolation was found to significantly reduce freezing behavior (p<0.001). An increase in the freezing response among IC mice was observed following the administration of varying doses of sumatriptan, as indicated by a one-way ANOVA analysis (p<0.001). However, the mitigating effects of sumatriptan were reversed upon the administration of GR-127935. An ELISA assay conducted before and after the passive avoidance test revealed no significant change in serum corticosterone levels among SC mice. In contrast, a significant increase was observed among IC mice, suggesting hyper-responsiveness of the HPA axis in isolated animals. This hyper-responsiveness was ameliorated following the administration of sumatriptan. Furthermore, both the sumatriptan and SC groups exhibited a similar trend, showing a significant increase in the expression of hippocampal glucocorticoid receptors following the stress of the passive avoidance test. Lastly, the elevated production of inflammatory cytokines (TNF-α, IL-1ß) observed following social isolation was attenuated in the sumatriptan group. CONCLUSION: Sumatriptan improved fear learning probably through modulation of HPA axis and hippocampus neuroinflammation.
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Sistema Hipotálamo-Hipofisário , Sumatriptana , Camundongos , Animais , Sistema Hipotálamo-Hipofisário/metabolismo , Sumatriptana/farmacologia , Sumatriptana/metabolismo , Receptores de Glucocorticoides/metabolismo , Serotonina/metabolismo , Doenças Neuroinflamatórias , Sistema Hipófise-Suprarrenal/metabolismo , Corticosterona , Estresse Psicológico/metabolismo , Isolamento Social , MedoRESUMO
INTRODUCTION: Idiopathic pulmonary fibrosis (IPF) is a fibrotic lung condition that produces symptoms including coughing which may cause by excessive accumulation of scar tissue inflammatory and oxidative stress exacerbation. Sumatriptan, utilized for migraine treatment as a selective 5-HT1B/1D receptor agonist, has demonstrated significant anti-inflammatory and antioxidant properties in multiple preclinical investigations. Operating primarily on serotonin receptors, sumatriptan leverages the diverse physiological functions of serotonin, playing a pivotal role in regulating both inflammation and oxidative stress which is particularly relevant in the context of IPF. MATERIALS & METHODS: Thirty-five male Wistar rats were divided to five group, including: Sham (without IPF induction), control (BLM 5â¯mg/kg, intraperitoneally), and three fibrosis group with sumatriptan (0.5, 1, and 3â¯mg/kg, i.p. for 2 weeks) administration. IPF was induced by injection of BLM (single dose, 5â¯mg/kg intratracheally). Lung tissues were separated for measurement of myeloperoxidase (MPO) as an oxidative stress hallmark, and tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-ß), and transforming growth factor-ß (TGF-ß) as inflammatory markers as well as alpha smooth muscle actin (α-SMA). Also, for histological investigations, tissue damages were assessed by Hematoxylin-eosin (H&E) and Masson's trichrome staining method. RESULTS: BLM-induced fibrosis could increase α-SMA, MPO, TNF-α, IL-1ß, and TGF-ß, while treatment with sumatriptan has reversed the α-SMA, MPO, and IL-1ß levels. Moreover, the results of H&E and Masson's trichrome staining indicated that sumatriptan (1 and 3â¯mg/kg) reduced tissue damages, alveolar wall thickness, collagen accumulation, and pulmonary fibrosis induced by BLM. CONCLUSION: According to the data achieved from this study, Sumatriptan appears to have therapeutic benefits in IPF, possibly via reducing α-SMA as well as inflammation and the toxicity caused by oxidative stress.
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Actinas , Bleomicina , Inflamação , Estresse Oxidativo , Fibrose Pulmonar , Ratos Wistar , Sumatriptana , Animais , Bleomicina/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Masculino , Sumatriptana/farmacologia , Ratos , Actinas/metabolismo , Inflamação/patologia , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inflamação/induzido quimicamente , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/tratamento farmacológico , Fibrose Pulmonar/metabolismo , Fibrose Pulmonar/patologia , Pulmão/patologia , Pulmão/efeitos dos fármacos , Pulmão/metabolismoRESUMO
BACKGROUND AND PURPOSE: Multiple drugs targeting the calcitonin gene-related peptide (CGRP) receptor have been developed for migraine treatment. Here, the effect of the monoclonal antibody erenumab on CGRP-induced vasorelaxation was investigated in human isolated blood vessels, as well as the effect of combining erenumab with the small molecule drugs, namely rimegepant, olcegepant, or sumatriptan. EXPERIMENTAL APPROACH: Concentration-response curves to CGRP, adrenomedullin or pramlintide were constructed in human coronary artery (HCA) and human middle meningeal artery (HMMA) segments, incubated with or without erenumab and/or olcegepant. pA2 or pKb values were calculated to determine the potency of erenumab in both tissues. To study whether acutely acting antimigraine drugs exerted additional CGRP-blocking effects on top of erenumab, HCA segments were incubated with a maximally effective concentration of erenumab (3 µM), precontracted with KCl and exposed to CGRP, followed by rimegepant, olcegepant, or sumatriptan in increasing concentrations. KEY RESULTS: Erenumab shifted the concentration-response curve to CGRP in both vascular tissues. However, in HCA, the Schild plot slope was significantly smaller than unity, whereas this was not the case in HMMA, indicating different CGRP receptor mechanisms in these tissues. In HCA, rimegepant, olcegepant and sumatriptan exerted additional effects on CGRP on top of a maximal effect of erenumab. CONCLUSIONS AND IMPLICATIONS: Gepants have additional effects on top of erenumab for CGRP-induced relaxation and could be effective in treating migraine attacks in patients already using erenumab as prophylaxis.
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Anticorpos Monoclonais Humanizados , Antagonistas do Receptor do Peptídeo Relacionado ao Gene de Calcitonina , Vasos Coronários , Artérias Meníngeas , Sumatriptana , Humanos , Anticorpos Monoclonais Humanizados/farmacologia , Vasos Coronários/efeitos dos fármacos , Artérias Meníngeas/efeitos dos fármacos , Antagonistas do Receptor do Peptídeo Relacionado ao Gene de Calcitonina/farmacologia , Sumatriptana/farmacologia , Masculino , Pessoa de Meia-Idade , Feminino , Relação Dose-Resposta a Droga , Piperidinas/farmacologia , Anticorpos Monoclonais/farmacologia , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Vasodilatação/efeitos dos fármacos , Piperazinas/farmacologia , Quinazolinas/farmacologia , Transtornos de Enxaqueca/tratamento farmacológico , Transtornos de Enxaqueca/metabolismo , Técnicas In Vitro , Idoso , Adulto , PiridinasRESUMO
BACKGROUND AND PURPOSE: Little is known of how cranial autonomic symptoms (CAS) in cluster headache and migraine may contribute to their severe headache phenotype. This strong association suggests the involvement of the cranial parasympathetic efferent pathway. To investigate its contribution, we studied the role of pituitary adenylate cyclase activating polypeptide-38 (PACAP-38), a potent sensory and parasympathetic neuropeptide, in modulating pre- and post-ganglionic cranial parasympathetic projection neurons, and their influence on headache-related trigeminal-autonomic responses. EXPERIMENTAL APPROACH: Using PACAP-38 and PACAP-38 responsive receptor antagonists, electrophysiological, behavioural and facial neurovascular-blood flow was measured in rats to probe trigeminal- and parasympathetic-neuronal, periorbital thresholds and cranial-autonomic outcomes, as they relate to primary headaches. KEY RESULTS: Sumatriptan attenuated the development of PACAP-38 mediated activation and sensitization of trigeminocervical neurons and related periorbital allodynia. PACAP-38 also caused activation and enhanced responses of dural-responsive pre-ganglionic pontine-superior salivatory parasympathetic neurons. Further, the PACAP-38 responsive receptor antagonists dissected a role of VPAC1 and PAC1 receptors in attenuating cranial-autonomic and trigeminal-neuronal responses to activation of the cranial parasympathetic projection, which requires post-ganglionic parasympathetic neurotransmission. CONCLUSION AND IMPLICATIONS: Given the prevailing view that sumatriptan acts to some degree via a peripheral mechanism, our data support that PACAP-38 mediated receptor activation modulates headache-related cranial-autonomic and trigeminovascular responses via peripheral and central components of the cranial parasympathetic projection. This provides a mechanistic rationale for the association of CAS with more severe headache phenotypes in cluster headache and migraine, and supports the cranial parasympathetic projection as a potential novel locus for treatment by selectively targeting PACAP-38 or PACAP-38 responsive VPAC1 /PAC1 receptors.
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Cefaleia Histamínica , Transtornos de Enxaqueca , Ratos , Animais , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/farmacologia , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/metabolismo , Sumatriptana/farmacologia , Transtornos de Enxaqueca/tratamento farmacológico , Transtornos de Enxaqueca/metabolismo , CefaleiaRESUMO
Among numerous approaches to the study of migraine, the nitroglycerin (NTG) model occupies a prominent place, but there is relatively insufficient information about how NTG affects intracranial vessels. In this study we aim to assess the effects of NTG on blood-flow parameters in meningeal vessels measured by imaging photoplethysmography (iPPG) in animal experiments. An amplitude of the pulsatile component (APC) of iPPG waveform was assessed before and within 2.5 h after the NTG administration in saline (n = 13) or sumatriptan (n = 12) pretreatment anesthetized rats in conditions of a closed cranial window. In animals of both groups, NTG caused a steady decrease in blood pressure. In 7 rats of the saline group, NTG resulted in progressive increase in APC, whereas decrease in APC was observed in other 6 rats. In all animals in the sumatriptan group, NTG administration was accompanied exclusively by an increase in APC. Diametrically opposite changes in APC due to NTG indicate a dual effect of this drug on meningeal vasomotor activity. Sumatriptan acts as a synergist of the NTG vasodilating action. The results we obtained contribute to understanding the interaction of vasoactive drugs in the study of the headache pathophysiology and methods of its therapy.
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Transtornos de Enxaqueca , Nitroglicerina , Ratos , Animais , Nitroglicerina/farmacologia , Nitroglicerina/uso terapêutico , Sumatriptana/farmacologia , Sumatriptana/uso terapêutico , Vasodilatadores/farmacologia , Vasodilatadores/uso terapêutico , Fotopletismografia , Transtornos de Enxaqueca/tratamento farmacológicoRESUMO
AIM: Evidence from mouse models suggests that brain serotonergic pathways control blood glucose. We hypothesized that sumatriptan (5HT1B -receptor agonist) would alter glucose homeostasis in humans. MATERIALS AND METHODS: We conducted a two-visit random-order double-blinded placebo-controlled cross-over trial in 10 overweight adults that were otherwise healthy. Participants received sumatriptan (single dose, 100 mg) or placebo before undergoing a 60-min intravenous glucose tolerance test, followed by a 120-min hyperinsulinaemic euglycaemic clamp. RESULTS: Glucose excursion was greater during intravenous glucose tolerance test with sumatriptan compared with placebo [iAUC0-60 min 316 (268-333) vs. 251 (197-319) min/mmol/L p = .047]. This was probably explained by a combination of reduced circulating insulin levels [iAUC0-10 min 1626 (1103-2733) vs. 2336 (1702-3269) min/pmol/L, p = .005], reduced insulin sensitivity [M/I-value 2.11 (1.15, 4.05) vs. 3.03 (1.14, 4.90) mg/kg/min per pmol/L, p = .010] and glucose effectiveness [SG 0.17 (0.12, 0.21) vs. 0.22 (0.18, 0.65)/min, p = .027]. CONCLUSIONS: 5HT1B receptors have a glucoregulatory role in humans, probably acting on insulin secretion, insulin sensitivity and glucose effectiveness.
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Glucose , Resistência à Insulina , Adulto , Animais , Camundongos , Humanos , Glucose/metabolismo , Sobrepeso/complicações , Sobrepeso/tratamento farmacológico , Secreção de Insulina , Sumatriptana/farmacologia , Sumatriptana/uso terapêutico , Serotonina , Estudos Cross-Over , Insulina/metabolismo , Glicemia/metabolismo , Método Duplo-CegoRESUMO
The current study was aimed to investigate the beneficial effect of sumatriptan, a 5-hydroxytryptamine 1B/1D (5HT1B/1D ) receptor agonist, on gastric ulcer in rats via stimulating 5HT1B/1D receptors and suppressing pro-inflammatory cytokines. Rats were allocated into three models of gastric ulcer: indomethacin (30 mg/kg, PO), water immersion restraint stress (WRS) and ethanol (5 ml/kg PO). Animals were administered with sumatriptan (0.01, 0.1, 0.3 and 1 mg/kg, i.p) 30 min before gastric ulcer induction. GR-127935 (0.01 mg/kg, i.p, a selective 5HT1B/1D antagonist) was administered 30 min before sumatriptan (0.1 mg/kg) injection. Macroscopic assessments (J-score), ELISA analysis of tumour necrosis factor-alpha (TNF-α) and interleukin-1beta (IL-1ß) and histopathological changes were performed on the rat's stomach tissues. Gastric ulcer induction in three models caused an increase in J-score, TNF-α, IL-1ß and microscopic features. Sumatriptan (0.1 mg/kg) significantly improved gastric injury induced by indomethacin, WRS and ethanol through the reduction in the J-score, TNF-α, IL-1ß and microscopic lesions. Concurrent administration of GR-127935 (0.01 mg/kg) with sumatriptan (0.1 mg/kg) reversed the gastroprotective effect of sumatriptan in three models. Sumatriptan possessed gastroprotective effects on indomethacin-, WRS- and ethanol-induced gastric damage in rats via the possible involvement of the 5HT1B/1D receptors.
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Úlcera Gástrica , Sumatriptana , Ratos , Masculino , Animais , Sumatriptana/farmacologia , Citocinas , Indometacina/farmacologia , Serotonina , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/tratamento farmacológico , Úlcera Gástrica/prevenção & controle , Fator de Necrose Tumoral alfa , Ratos Wistar , Etanol/toxicidadeRESUMO
BACKGROUND: Mesenteric ischemia has remained without effective pharmacological management for many years. Sumatriptan, an abortive medication for migraine and cluster headaches, has potent anti-inflammatory properties and ameliorated organ ischemia in previous animal studies. Similarly, inhibition of the kynurenine pathway ameliorated renal and myocardial ischemia/reperfusion (I/R) in many preclinical studies. Herein, we assessed the effect of sumatriptan on experimental mesenteric I/R and investigated whether kynurenine pathway inhibition is a mechanism underlying its action. METHODS: Ischemia was induced by ligating the origin of the superior mesenteric artery (SMA) and its anastomosis with the inferior mesenteric artery (IMA) with bulldog clamps for 30 min. Ischemia was followed by 1 h of reperfusion. Sumatriptan (0.1, 0.3, and 1 mg/kg ip) was injected 5 min before the reperfusion phase, 1-methyltryptophan (1-MT) (100 mg/kg iv) was used to inhibit kynurenine production. At the end of the reperfusion phase, samples were collected from the jejunum of rats for H&E staining and molecular assessments. RESULTS: Sumatriptan improved the integrity of intestinal mucosa after I/R, and 0.1 mg/kg was the most effective dose of sumatriptan in this study. Sumatriptan decreased the increased levels of TNF-α, kynurenine, and p-ERK but did not change the decreased levels of NO. Furthermore, sumatriptan significantly increased the decreased ratio of Bcl2/Bax. Similarly, 1-MT significantly decreased TNF-α and kynurenine and protected against mucosal damage. CONCLUSIONS: This study demonstrated that sumatriptan has protective effects against mesenteric ischemia and the kynurenine inhibition is potentially involved in this process. Therefore, it can be assumed that sumatriptan has the potential to be repurposed as a treatment for acute mesenteric ischemia.
Assuntos
Isquemia Mesentérica , Traumatismo por Reperfusão , Ratos , Animais , Isquemia Mesentérica/tratamento farmacológico , Sumatriptana/farmacologia , Sumatriptana/uso terapêutico , Cinurenina , Traumatismo por Reperfusão/metabolismo , Fator de Necrose Tumoral alfa , IsquemiaRESUMO
Scientific literature describes that sumatriptan is metabolized by oxidative deamination of its dimethylaminoethyl residue by monoamine oxidase A (MAO A) and not by cytochrome P450 (CYP)-mediated demethylation, as is usual for such structural elements. Using recombinant human enzymes and HPLC-MS analysis, we found that CYP enzymes may also be involved in the metabolism of sumatriptan. The CYP1A2, CYP2C19, and CYP2D6 isoforms converted this drug into N-desmethyl sumatriptan, which was further demethylated to N,N-didesmethyl sumatriptan by CYP1A2 and CYP2D6. Otherwise, sumatriptan and its two desmethyl metabolites were metabolized by recombinant MAO A but not by MAO B to the corresponding acetaldehyde, with sumatriptan being only a poor substrate for MAO A compared to the N-demethylated and the N,N-didemethylated derivatives.
Assuntos
Sistema Enzimático do Citocromo P-450 , Microssomos Hepáticos , Sumatriptana , Humanos , Citocromo P-450 CYP1A2/metabolismo , Citocromo P-450 CYP2D6/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Microssomos Hepáticos/metabolismo , Monoaminoxidase/metabolismo , Sumatriptana/metabolismo , Sumatriptana/farmacologiaRESUMO
BACKGROUND: The exact mechanism and site of action of triptans in aborting migraine attacks remain under debate. We hypothesized that the clinical efficacy of triptans lies in aborting central sensitization and focused on the question of why triptans are headache specific, that is highly effective in migraine and cluster headache and ineffective in extracephalic pain. METHODS: Forty healthy participants were enrolled in this double-blinded, randomized, placebo-controlled study. The effect of sumatriptan (n = 20) versus placebo (n = 20) was investigated in a trigeminal (V1) versus an extracephalic dermatome (forearm) using a topical capsaicin sensitization model. Capsaicin-induced primary and secondary hyperalgesia were evaluated using quantitative sensory testing. RESULTS: After capsaicin application, primary hyperalgesia developed in both the sumatriptan and placebo groups in both dermatomes. However, sumatriptan exclusively prevented secondary hyperalgesia in the V1 dermatome but not on the forearm. Placebo exerted no effects on secondary hyperalgesia in both trigeminal and extracephalic dermatomes. Additionally, sumatriptan reduced the flare size exclusively in the V1 dermatome. CONCLUSIONS: Our data suggest that sumatriptan reduces central sensitization (secondary hyperalgesia) without modulating peripheral sensitization (primary hyperalgesia) in a human pain model of capsaicin-induced sensitization. Moreover, despite a systemic administration of sumatriptan, the modulatory effects are trigeminal specific, echoing the clinical effect of triptans in aborting headaches, but not extracephalic pain. SIGNIFICANCE: Our data suggest that triptans exert their efficacy by suppressing central sensitization. By revealing a dermatome-specific modulation, our study demonstrates a previously unrecognized interaction between the pharmacodynamics of triptans and the trigeminal nociceptive system that provides new insight into how triptans may work in aborting headache attacks.
Assuntos
Transtornos de Enxaqueca , Sumatriptana , Capsaicina/farmacologia , Capsaicina/uso terapêutico , Sensibilização do Sistema Nervoso Central , Cefaleia/induzido quimicamente , Cefaleia/tratamento farmacológico , Humanos , Hiperalgesia/induzido quimicamente , Hiperalgesia/tratamento farmacológico , Transtornos de Enxaqueca/tratamento farmacológico , Dor/tratamento farmacológico , Sumatriptana/farmacologia , Sumatriptana/uso terapêutico , Triptaminas/efeitos adversosRESUMO
Migraine is a frequent neurological condition characterized by throbbing headaches, nausea, photophobia, and phonophobia, among other symptoms. Sumatriptan belongs to a BCS class III, which exhibits poor oral bioavailability and several side-effects. The objective of the present study was to develop solid lipid nanoparticles (SLNPs) of sumatriptan succinate for brain targeting by nasal route. Solvent injection method was used to increase the entrapment efficiency of hydrophilic drug. Thus, formulation was optimized by central composite design with minimum particle size, optimized zeta potential, and maximum entrapment efficiency, which was found to be 133.4 nm, -17.7 mV, and 75.5%, respectively. Optimized batch was further evaluated for surface morphology, Fourier-transform infrared spectroscopy, in vitro release, permeation across nasal mucosa, and histopathology. It was seen that most of the particles were spherical in shape as confirmed by scanning electron microscopy and transmission electron microscopy. The release of drug through the lipid showed initial burst release followed by sustained release up to 12 h. The ex vivo diffusion study using goat nasal mucosa at pH 6.8 revealed that SLNPs permeation across nasal mucosa was quick, which was sufficient for brain targeting. Histopathology studies further revealed integrity of nasal mucosa after treatment with SLNPs. The investigation indicated that hydrophilic drug, sumatriptan succinate can be successfully entrapped in SLNPs to target brain via nasal delivery, and thus it could be an effective approach for nose-to-brain delivery.
Assuntos
Nanopartículas , Sumatriptana , Administração Intranasal , Encéfalo , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Lipossomos , Nanopartículas/química , Mucosa Nasal , Tamanho da Partícula , Polímeros , Sumatriptana/química , Sumatriptana/farmacologiaRESUMO
Transcranial Doppler ultrasonography is used to study intracranial blood flow changes associated with migraine in humans, but whether this method is helpful in preclinical settings is yet unknown. To identify changes in rat intracranial blood flow specific to trigeminovascular activation-a key process in migraine pathophysiology-we measured Doppler indices in the middle cerebral artery and basilar artery before, during, and after dural or somatosensory electrical stimulation. Hemodynamic changes specific to dural stimulation were tested further in separate experiments. After baseline recordings, the animals received cumulative infusions of valproate (100 mg/kg, trice), sumatriptan (0.3, 1, and 3 mg/kg), or saline, and dural stimulation with measurement of Doppler indices was repeated every 10 min for 1 h. Several parameters of blood flow in the rat middle cerebral artery underwent alterations specific to trigeminovascular activation. These changes, however, were insensitive to valproate and sumatriptan and diminished over time. These findings question the reliability of blood flow velocity variations in large intracranial vessels as biological markers of migraine-related processes and do not support the idea of using transcranial Doppler ultrasonography for preclinical screening of antimigraine treatments, at least in the model of acute trigeminovascular activation in rats.
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Transtornos de Enxaqueca , Ultrassonografia Doppler Transcraniana , Animais , Velocidade do Fluxo Sanguíneo/fisiologia , Circulação Cerebrovascular , Humanos , Transtornos de Enxaqueca/diagnóstico por imagem , Transtornos de Enxaqueca/tratamento farmacológico , Ratos , Reprodutibilidade dos Testes , Sumatriptana/farmacologia , Sumatriptana/uso terapêutico , Ultrassonografia Doppler Transcraniana/métodos , Ácido Valproico/farmacologiaRESUMO
Mucosal inflammation in colitis is associated with changes in the intestinal serotonin (5-HT) level. Sumatriptan, a 5-HT1B/1D receptor agonist, has demonstrated anti-inflammatory characteristics. The purpose of this study was to determine the effects of sumatriptan in a rat model of acute experimental colitis and to elucidate the probable participation of presynaptic 5-HT1B/1D receptors. To induce colitis, acetic acid (4%) was injected intrarectally. Treatments were given intraperitoneally (IP) once daily over 3 consecutive days starting 1-h post-induction. Sumatriptan was given at 0.5, 1, 2, and 5 mg/kg. GR-127935, a 5-HT1B/1D receptor antagonist, was injected (0.1 and 0.3 mg/kg) 30 min prior to the most effective dose of sumatriptan (1 mg/kg). On day 4, the colon samples were isolated. Significant enhancements of the tissue tumor necrosis factor-alpha (TNF-α), myeloperoxidase (MPO), microscopic and macroscopic damages, body weight losses, and also reductions in tissue superoxide dismutase (SOD) and 5-HT were observed in colitis rats. On the other hand, sumatriptan at doses 0.5, 1, and 2 mg/kg could diminish pathologic changes in the measured biomarkers, histopathologic damages, and body weight losses. Although GR-127935 at dose 0.3 mg/kg could markedly improve the pathologic indexes, its sub-effective dose (0.1 mg/kg) reversed the protective effect of sumatriptan (1 mg/kg). Moreover, sumatriptan (1 and 5 mg/kg) and GR-127935 (0.3 mg/kg) increased the serotonin level. Post-treatment with low-dose sumatriptan demonstrated a protective impact on this peripheral inflammatory condition. Notably, this protective effect may be mediated, at least in part, through 5-HT1B/1D receptors, as well as anti-inflammatory and anti-oxidative characteristics.
Assuntos
Colite , Sumatriptana , Ácido Acético , Animais , Colite/induzido quimicamente , Colite/tratamento farmacológico , Ratos , Serotonina/farmacologia , Sumatriptana/farmacologia , Sumatriptana/uso terapêutico , Redução de PesoRESUMO
INTRODUCTION: Recent investigations have indicated the potential therapeutic role of cannabinoid type 2 (CB2) receptors in various inflammatory-related disorders. However, the role of these receptors has not been studied in skin flap models to date. In this study, we aimed to evaluate the possible involvement of CB2 receptors in the anti-inflammatory effects of sumatriptan, improving the random-pattern skin flap survival in rats. METHODS: In a controlled experimental study, 36 male Wistar rats were randomly divided into 6 study groups (n = 6 per group). Two doses of sumatriptan (0.1 and 0.3 mg/kg) were administered intraperitoneally 30 min before harvesting the flap tissue. In a separate group, SR144528 (a selective CB2 receptor inverse agonist) was injected before the most effective dose of sumatriptan to determine the possible involvement of CB2 receptors in its action. Histopathological examinations, the expression level of CB2 receptors (Western blot analysis), and IL-1ß and TNF-α concentrations (ELISA) were explored in the skin flap sampled tissues. RESULTS: Sumatriptan 0.3 mg/kg remarkably enhanced the skin flap survival in all macroscopic and microscopic investigations compared to the control group (p < 0.001). IL-1ß and TNF-α levels were significantly attenuated (p < 0.001), and the expression of CB2 receptors in skin cells was amplified in rats treated with sumatriptan 0.3 mg/kg (p < 0.05) compared to the control group. However, the administration of SR144528 (2 mg/kg) nullified all the protective effects of sumatriptan 0.3 mg/kg. CONCLUSION: We discovered that CB2 receptors play a crucial role in the favorable effects of sumatriptan on skin flap survival as a novel mechanism of action. So, targeting these receptors seems to be a dependable method in skin flap surgeries to ensure its survival and prevent tissue necrosis. Further experimental and clinical investigations are needed to ensure the safe clinical application of this method.
Assuntos
Canabinoides , Sumatriptana , Ratos , Masculino , Animais , Sumatriptana/farmacologia , Ratos Wistar , Fator de Necrose Tumoral alfa/metabolismo , Receptores de Canabinoides , Agonismo Inverso de Drogas , Canabinoides/farmacologiaRESUMO
Sepsis is a severe systemic inflammatory response with high mortality rate resulting from different microorganisms. Cytokines activation is essential for the immune response, but in painful conditions like sepsis, cytokines act as a double-edged sword and dysregulate immune response which is life-threatening owing to multiple organ dysfunction. The abnormality in 5-HT function is involved in pathological conditions like irritable bowel syndrome, inflammation, myocardial ischemia, itch and renal injury. Sumatriptan, a 5-HT1B/1D agonist, has anti-inflammatory and anti-oxidative stress effects on animal models. This study was aimed to assess the effects of sumatriptan on kidney injury, the levels of pro-inflammatory cytokines and the percentage of survival in (CLP)-induced sepsis were examined.Cecal ligation and puncture (CLP) model was done on adult C57BL/6 male mice to induce Polymicrobial sepsis. Sumatriptan was injected intraperitoneally 1 h after the sepsis induction by CLP at doses of 0.1, 0.3, and 1 mg/kg in 3 treatment groups. To study the effect of sumatriptan on short-term survival, septic animals were detected 72 h after CLP. Serum levels of TNF-α, IL-1ß, IL-6 and IL-10 were evaluated. To study sepsis-induced acute renal failure, kidney functional biomarkers and histopathological alterations were evaluated.Sumatriptan (0.3 mg/kg) administration significantly enhanced survival rate (P<0.01) compared to the CLP group. The beneficial effects of sumatriptan were related to a significant decrease in the pro-inflammatory cytokines and elevated level of IL-10. Sumatriptan presented protective effects on kidney biomarkers and histopathology assay.Anti-inflammatory effects of sumatriptan lead to decrease mortality rate and inflammatory cytokines in CLP induction sepsis in C57BL/6 mice.
Assuntos
Sepse , Sumatriptana , Animais , Citocinas , Modelos Animais de Doenças , Rim , Ligadura , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Punções , Sepse/complicações , Sepse/tratamento farmacológico , Sumatriptana/farmacologia , Sumatriptana/uso terapêuticoRESUMO
Seizure occurs as a result of uncontrolled electrical disturbances within the brain. Various biomolecules such as N-methyl-D-aspartate (NMDA), nitric oxide (NO), and cAMP response element-binding protein (CREB) have been implicated in the pathophysiology of seizure. Sumatriptan is a specific 5-Hydroxytryptamine 1B/1D receptor agonist and has neuroprotective effects in various neuropsychiatric disorders. In the current study, we tried to investigate the possible interaction of sumatriptan with NMDA/NO and CREB signaling pathway in PTZ induced seizure. For this purpose, various agonist and antagonist of NMDA such as MK-801 and Ketamine, NO precursor L-ARG, and NOS inhibitors L-NAME and 7-NI were co-administered with sumatriptan in PTZ induced seizure model. The level of nitrite in mice hippocampus was determined by Griess reaction. The gene expression of NR1, NR2A, NR2B, and CREB were quantified by quantitative real time-polymerase chain reaction (qRT-PCR). Furthermore, the involved neuronal nitric oxide synthase (nNOS) protein expression was examined via western blot analysis. Effective dose of sumatriptan (1.2 mg/kg) alone and subeffective dose of sumatriptan (0.3 mg/kg) in combination with NMDA and/or NO antagonist showed significant (P < 0.001) anticonvulsant activity in mice. Furthermore, sumatriptan significantly inhibited the PTZ-induced mRNA expression of NR2A (P < 0.0001), NR2B (P < 0.05), and CREB (P < 0.01). Also, the expression of nNOS protein in PTZ treated group was reversed by sumatriptan (P < 0.01). Hence, current findings suggest that the anticonvulsant effect of sumatriptan was due to down regulation of NMDA/NO and CREB signaling pathway.
Assuntos
Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico , Fármacos Neuroprotetores , Convulsões , Sumatriptana , Animais , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Camundongos , N-Metilaspartato/farmacologia , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Óxido Nítrico/metabolismo , Pentilenotetrazol/farmacologia , Convulsões/induzido quimicamente , Convulsões/tratamento farmacológico , Convulsões/prevenção & controle , Transdução de Sinais , Sumatriptana/farmacologia , Sumatriptana/uso terapêuticoRESUMO
OBJECTIVE: Determination of possible sex differences in mechanisms promoting migraine progression and the contribution of prolactin and the prolactin long (PRLR-L) and short (PRLR-S) receptor isoforms. BACKGROUND: The majority of patients with chronic migraine and medication overuse headache are female. Prolactin is present at higher levels in women and increases migraine. Prolactin signaling at the PRLR-S selectively sensitizes nociceptors in female rodents, while expression of the PRLR-L is protective. METHODS: Medication overuse headache was modeled by repeated sumatriptan administration in male and female mice. Periorbital and hindpaw cutaneous allodynia served as a surrogate of migraine-like pain. PRLR-L and PRLR-S isoforms were measured in the trigeminal ganglion with western blotting. Possible co-localization of PRLR with serotonin 5HT1B and 5HT1D receptors was determined with RNAscope. Cabergoline, a dopamine receptor agonist that inhibits circulating prolactin, was co-administered with sumatriptan. Nasal administration of CRISPR/Cas9 plasmid was used to edit expression of both PRLR isoforms. RESULTS: PRLR was co-localized with 5HT1B or 5HT1D receptors in the ophthalmic region of female trigeminal ganglion. A single injection of sumatriptan increased serum PRL levels in female mice. Repeated sumatriptan promoted cutaneous allodynia in both sexes but down-regulated trigeminal ganglion PRLR-L, without altering PRLR-S, only in females. Co-administration of sumatriptan with cabergoline prevented allodynia and down-regulation of PRLR-L only in females. CRISPR/Cas9 editing of both PRLR isoforms in the trigeminal ganglion prevented sumatriptan-induced periorbital allodynia in females. INTERPRETATION: We identified a sexually dimorphic mechanism of migraine chronification that involves down-regulation of PRLR-L and increased signaling of circulating prolactin at PRLR-S. These studies reveal a previously unrecognized neuroendocrine mechanism linking the hypothalamus to nociceptor sensitization that increases the risk of migraine pain in females and suggest opportunities for novel sex-specific therapies including gene editing through nasal delivery of CRISPR/Cas9 constructs.
Assuntos
Transtornos da Cefaleia Secundários , Transtornos de Enxaqueca , Animais , Feminino , Humanos , Hiperalgesia/induzido quimicamente , Masculino , Camundongos , Transtornos de Enxaqueca/induzido quimicamente , Transtornos de Enxaqueca/metabolismo , Prolactina/efeitos adversos , Prolactina/metabolismo , Sumatriptana/farmacologiaRESUMO
The liver detoxifies and metabolizes many drugs and xenobiotics which may cause hepatotoxicity due to some toxic agents. Carbon tetrachloride (CCl4) is metabolized in cytochrome P450 and its reactive radical metabolites cause lipid peroxidation, cellular injury, and apoptosis. Sumatriptan (SUM), 5-HT1B/1D receptor agonist, had anti-inflammatory and anti-oxidant effects. In this research the effect of SUM pre-treatment against CCl4-induced hepatotoxicity was examined. Adult rats received SUM (0.1, 0.3 and 1 mg/kg; i.p.) for 3 consecutive days before CCl4 (2 ml/kg; i.p. on the 3rd day). The aminotransferases serum levels, tissue levels of anti-oxidant and pro-inflammatory markers and histopathological examination were evaluated. SUM (0.3 mg/kg) prevented significantly the elevation of aminotransferases versus the control group (CCl4 group) (P<0.0001) and also, reversed meaningfully the changes of the MPO, MDA, SOD and CAT, IL-1ß and TNF-α levels. Additionally, CCl4-intoxication resulted to the disruption of lobular and cellular structures and inflammation in histopathological evaluation which is prevented by SUM (0.3 mg/kg). These data revealed that SUM (0.3 mg/kg), but no at doses 0.1 and 1 mg/kg, decreases the hepatotoxicity of induced by CCl4 in rats.
Assuntos
Tetracloreto de Carbono , Doença Hepática Induzida por Substâncias e Drogas , Animais , Anti-Inflamatórios/farmacologia , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Tetracloreto de Carbono/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Peroxidação de Lipídeos , Fígado/metabolismo , Estresse Oxidativo , Ratos , Sumatriptana/farmacologiaRESUMO
Migraine attacks are delimited, allowing investigation of changes during and outside attack. Gene expression fluctuates according to environmental and endogenous events and therefore, we hypothesized that changes in RNA expression during and outside a spontaneous migraine attack exist which are specific to migraine. Twenty-seven migraine patients were assessed during a spontaneous migraine attack, including headache characteristics and treatment effect. Blood samples were taken during attack, two hours after treatment, on a headache-free day and after a cold pressor test. RNA-Sequencing, genotyping, and steroid profiling were performed. RNA-Sequences were analyzed at gene level (differential expression analysis) and at network level, and genomic and transcriptomic data were integrated. We found 29 differentially expressed genes between 'attack' and 'after treatment', after subtracting non-migraine specific genes, that were functioning in fatty acid oxidation, signaling pathways and immune-related pathways. Network analysis revealed mechanisms affected by changes in gene interactions, e.g. 'ion transmembrane transport'. Integration of genomic and transcriptomic data revealed pathways related to sumatriptan treatment, i.e. '5HT1 type receptor mediated signaling pathway'. In conclusion, we uniquely investigated intra-individual changes in gene expression during a migraine attack. We revealed both genes and pathways potentially involved in the pathophysiology of migraine and/or migraine treatment.
Assuntos
Transtornos de Enxaqueca/genética , Transcriptoma/genética , Adolescente , Adulto , Idoso , Epistasia Genética/efeitos dos fármacos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos de Enxaqueca/tratamento farmacológico , RNA/genética , RNA/metabolismo , Sumatriptana/farmacologia , Sumatriptana/uso terapêutico , Adulto JovemRESUMO
BACKGROUND: Existent animal models of migraine are not without drawbacks and limitations. The aim of our study was to evaluate imaging photoplethysmography (PPG) as a method of assessing intracranial blood flow in rats and its changes in response to electrical stimulation of dural trigeminal afferents. METHODS: Experiments were carried out with 32 anesthetized adult male Wistar rats. Trigeminovascular system (TVS) was activated by means of electrical stimulation of dural afferents through a closed cranial window (CCW). Parameters of meningeal blood flow were monitored using a PPG imaging system under green illumination with synchronous recording of an electrocardiogram (ECG) and systemic arterial blood pressure (ABP). Two indicators related to blood-flow parameters were assessed: intrinsic optical signals (OIS) and the amplitude of pulsatile component (APC) of the PPG waveform. Moreover, we carried out pharmacological validation of these indicators by determining their sensitivity to anti-migraine drugs: valproic acid and sumatriptan. For statistical analysis the non-parametric tests with post-hoc Bonferroni correction was used. RESULTS: Significant increase of both APC and OIS was observed due to CCW electrical stimulation. Compared to saline (n = 11), intravenous administration of both the sumatriptan (n = 11) and valproate (n = 10) by using a cumulative infusion regimen (three steps performed 30 min apart) lead to significant inhibitory effect on the APC response to the stimulation. In contrast, intravenous infusion of any substance or saline did not affect the OIS response to the stimulation. It was found that infusion of either sumatriptan or valproate did not affect the response of ABP or heart rate to the stimulation. CONCLUSIONS: Imaging PPG can be used in an animal migraine model as a method for contactless assessment of intracranial blood flow. We have identified two new markers of TVS activation, one of which (APC) was pharmacologically confirmed to be associated with migraine. Monitoring of changes in APC caused by CCW electrical stimulation (controlling efficiency of stimulation by OIS) can be considered as a new way to assess the peripheral mechanism of action of anti-migraine interventions.