Calcitonin Gene-related Peptide Levels Research Articles

The Analgesic Effect and Potential Mechanisms of Acupuncture for Migraine Rats: A Systematic Review and Meta-Analysis.

To assess the inhibitory effect of acupuncture on pain symptoms in migraine models, and to further summarize the potential mechanisms of acupuncture in regulating hyperalgesia in the treatment of migraine. Literature search in databases such as China National Knowledge Infrastructure (CNKI), PubMed, and Web of Science (WOS) etc. The quality was evaluated by the Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE) bias risk assessment tool and Collaborative Approach to Meta-analysis and Review of Animal Data from Experimental Studies (CAMARADES) checklist. Meta-analyses were performed using Stata 17.0 software. Twenty-one studies involving 489 animals were identified. The qualitative score ranged from 3 to 9 points. Facial mechanical withdrawal threshold (FMWT) and paw mechanical withdrawal threshold (PMWT) measured by Von Frey filaments were selected as major outcomes, and serum calcitonin gene-related peptide (CGRP) levels measured by ELISA were selected as secondary outcome. Meta-analysis results revealed that true acupuncture (TA) group significantly increased FMWT, PMWT and CGRP compared to model group. TA group showed superior effect in FMWT, PMWT relative to sham acupuncture (SA) group. Subgroup analysis results showed that high risk of bias scores may be responsible for the high heterogeneity of FMWT; additionally, CGRP analysis suggests that acupoint selection and blood collection sites may be sources of heterogeneity. In the treatment of migraine pain symptoms, the underlying mechanism of acupuncture treatment is either the regulation of hyperalgesia and neurotransmitters, or the reduction of inflammatory factors. The results indicate that TA treatment effectively increased the pain threshold and reduced hyperalgesia in migraine rats. In summary, our study highlights the potential of TA as an effective treatment for migraine, but further investigation is required to fully comprehend its mechanism of action and optimize its clinical application.

CGRP, Migraine, and Brain MRI in CADASIL: A Pilot Study.

Migraine is associated with neuroimaging differences in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). However, it is unknown if migraine-related disability (MRD) or if calcitonin gene-related peptide (CGRP), a vasoactive peptide important in migraine pathology, have radiographic implications. The aims of this study were to identify whether MRD or interictal serum CGRP levels impacted neuroimaging findings for those with CADASIL. A cross-sectional analysis was performed. The primary outcomes were neuroimaging differences associated with MRD among those with migraine or interictal serum CGRP levels of those with and without migraine. MRD was defined by 2 migraine disability scales (Migraine Disability Assessment, Headache Impact Test-6). Retrospective brain magnetic resonance imaging was reviewed (average 1.7 ± 2.0y before enrollment). Rank-sum and χ 2 tests were used. Those with migraine (n=25, vs. n=14 without) were younger [median 49 (25 to 82)y vs. 60 (31 to 82)y, P <0.007], had fewer cerebral microbleeds (0 to 31 vs. 0 to 50, P =0.02) and less frequently had anterior temporal lobe T2 hyperintensities [68% (17/25) vs 100% (14/14), P =0.02]. MRD scale outcomes had no significant radiographic associations. Interictal serum CGRP did not differ (migraine: n=18, 27.0±9.6pg/mL vs. no migraine: n=10, 26.8±15.7pg/mL, P =0.965). Migraine may forestall microangiopathy in CADASIL, though possibly independent of severity as measured by MRD. Interictal serum CGRP did not differ in our cohort suggesting CGRP may not be vital to migraine pathophysiology in CADASIL. Larger studies are needed to account for age differences.

Calcitonin gene-related peptide (CGRP) concentrations outside migraine attacks in peripheral blood as a potential biomarker for chronic migraine

Abstract Introduction Chronic migraine is a debilitating condition that affects a significant portion of the population. Accurate diagnosis and treatment of chronic migraine remain a challenge due to the lack of objective biomarkers. Calcitonin gene-related peptide (CGRP) is a neuropeptide involved in the pathophysiology of migraine and has been proposed as a potential biomarker for migraine. Methods We measured CGRP levels in peripheral blood samples collected from 142 participants with chronic or episodic migraine and 24 healthy controls during ictal periods, i.e., outside migraine attacks. We compared CGRP levels between the three groups and assessed the correlation between CGRP levels and clinical features of chronic migraine. Conclusion Our study provides evidence that CGRP levels in peripheral blood during ictal periods may serve as a potential biomarker for chronic migraine. Further studies are needed to validate these findings and to explore the clinical utility of CGRP as a biomarker for chronic migraine.

Shaoyao Gancao decoction alleviates the central hyperalgesia of recurrent NTG-induced migraine in rats by regulating the NGF/TRPV1/COX-2 signal pathway

Ethnopharmacological relevanceShaoyao Gancao Decoction (SGD) is well known as an effective prescription for analgesia composed of two herbs, and is noted as traditional Chinese medicine morphine. It is widely used in various conditions causing pain, including migraine. However, there is currently no research exploring the mechanism of action in the treatment of migraines. Aim of the studyThe current research was devised to determine the underlying regulatory mechanism of SGD, by verifying its role in the NGF/TRPV1/COX-2 signal pathway. Materials and methodsThe active components in SGD were identified by UHPLC-MS. A migraine model was prepared by subcutaneous (s.c.) injection of nitroglycerin (NTG) into the neck to detect migraine-like behavior, orbital hyperalgesia threshold changes, and the therapeutic effect of SGD. The mechanism of SGD in remedying migraine was studied through transcriptome sequencing (RNA-seq), which was further validated utilizing Elisa, Reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blotting (WB) experiments. ResultsIn the SGD chemical composition analysis, 45 components were identified including gallic acid, paeoniflorin and albiforin. In the behavioral experiments, SGD treatment significantly decreased the score of migraine-like head scratching in the NTG-induced migraine model (Mod) rats, while the hyperalgesia threshold increased outstandingly on days 10, 12, and 14 (P < 0.01, P < 0.001 or P < 0.0001). In migraine biomarkers experiment, compared with the Mod group, the 5-hydroxytryptamine (5-HT) contents were outstandingly enhanced by SGD treatment, while nitric oxide (NO) contents were markedly declined (P < 0.01). In the RNA-seq test, the down-regulated genes of SGD inhibiting hyperalgesia migraine included the neurotrophic factor (NGF) and transient receptor potential vanillic acid subfamily protein 1 receptor (TRPV1). The down-regulation pathway is the inflammatory mediator regulation of TRP channels. In gene set enrichment analysis (GSEA), SGD decreased the over-expression of protooncogene tyrosine-protein kinase Src (SRC) and TRPV1 in this pathway, and the two genes clustered at its lower end, with similar functions. PPI network results show that NGF interacts with TRPV1. Further verification shows that when compared with Mod group, the plasma cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2) protein expression levels and the dura mater calcitonin gene-related peptide (CGRP), extracellular signal-regulated kinase (ERK), p-ERK, SRC and NGF protein expression levels in the SGD group were remarkably decreased (P < 0.01, P < 0.001 or P < 0.0001), and the expression level of TRPV1 protein showed a downward trend (P = 0.06). The expression levels of COX-2, NO, CGRP, TRPV1, SRC and NGF mRNA in the dura mater was overtly down-regulated (P < 0.05, P < 0.01 or P < 0.001). ConclusionsSGD has a significant inhibitory effect on the NGF/TRPV1/COX-2 signaling pathway that mediates central hyperalgesia migraine, thus suggesting the molecular mechanism of SGD in improving the symptoms of migraine may be related to the central hyperalgesia neurotransmitter that regulates the pathogenesis of migraine.

MIA mice exhibit enteric nerve defects and are more susceptible to dextran sulfate sodium-induced colitis

Maternal immune activation (MIA) during pregnancy impairs the development of the central nervous system as well as the peripheral nervous system. Emerging evidence indicates that individuals with MIA suffer more from gastrointestinal disorders. The present study aims to test the hypothesis that MIA-induced susceptibility to inflammatory bowel disease is due to defects in the innervation of mucosal sensory nerves. Acute dextran sulfate sodium (DSS) colitis was induced in MIA and control adult mice. Body weight loss, disease activity index and colonic histological changes were measured during colitis. The study found that MIA mice were hypersusceptible to DSS-induced colitis and that macrophage infiltration and cytokine production were elevated in the colon of MIA mice. In vitro experiments also demonstrated that colonic macrophages from MIA mice presented hyperinflammatory responses to LPS stimulation. Sensory nerve-secreted calcitonin gene–related peptide (CGRP) is an important neuropeptide in modulating enteric inflammation. Intriguingly, we found that CGRP-positive nerves were sparsely distributed in the colon of MIA mice regardless of DSS treatment. And the protein level of CGRP was significantly reduced in colon of MIA mice. However, there was no decrease in the number of CGRP-positive cell bodies in either the DRG or vagal ganglion, suggesting that innervation defects of CGRP mucosal sensory nerves exist in the colon of MIA mice. Critically, administration of recombinant CGRP to MIA mice during DSS colitis significantly reversed their hyperinflammatory pathology. Additionally, the hyperinflammatory phenotype of colonic macrophages of MIA mice could also be reversed by CGRP treatment in vitro. Collectively, these findings suggested that the sensor nerve innervation defect-induced CGRP deficiency in MIA mice participates in their increased susceptibility to colitis. Thus, sensor nerve-secreted CGRP may be a new therapeutic target for autism combined with inflammatory bowel disease.

TRPV1 activation in human Langerhans cells and T cells inhibits mucosal HIV-1 infection via CGRP-dependent and independent mechanisms

Upon its mucosal transmission, HIV type 1 (HIV-1) rapidly targets genital antigen-presenting Langerhans cells (LCs), which subsequently transfer infectious virus to CD4+ Tcells. We previously described an inhibitory neuroimmune cross talk, whereby calcitonin gene-related peptide (CGRP), a neuropeptide secreted by peripheral pain-sensing nociceptor neurons innervating all mucosal epithelia and associating with LCs, strongly inhibits HIV-1 transfer. As nociceptors secret CGRP following the activation of their Ca2+ ion channel transient receptor potential vanilloid 1 (TRPV1), and as we reported that LCs secret low levels of CGRP, we investigated whether LCs express functional TRPV1. We found that human LCs expressed mRNA and protein of TRPV1, which was functional and induced Ca2+ influx following activation with TRPV1 agonists, including capsaicin (CP). The treatment of LCs with TRPV1 agonists also increased CGRP secretion, reaching its anti-HIV-1 inhibitory concentrations. Accordingly, CP pretreatment significantly inhibited LCs-mediated HIV-1 transfer to CD4+ Tcells, which was abrogated by both TRPV1 and CGRP receptor antagonists. Like CGRP, CP-induced inhibition of HIV-1 transfer was mediated via increased CCL3 secretion and HIV-1 degradation. CP also inhibited direct CD4+ Tcells HIV-1 infection, but in CGRP-independent manners. Finally, pretreatment of inner foreskin tissue explants with CP markedly increased CGRP and CCL3 secretion, and upon subsequent polarized exposure to HIV-1, inhibited an increase in LC-Tcell conjugate formation and consequently Tcell infection. Our results reveal that TRPV1 activation in human LCs and CD4+ Tcells inhibits mucosal HIV-1 infection, via CGRP-dependent/independent mechanisms. Formulations containing TRPV1 agonists, already approved for pain relief, could hence be useful against HIV-1.

Effect of magnesium sulfate treatment on mediators of endothelial dysfunction and electrolytes in mild and severe preeclampsia: A case-control study.

Magnesium sulfate (MgSO4) treatment is widely used for the prevention of eclamptic seizures. However, its effect on mediators of endothelial dysfunction (ED) and electrolytes remains unclear. We evaluated the effects of MgSO4 treatment on mediators of ED and electrolytes. We recruited 100 women comprising 50 severe, 50 mild preeclampsia (PE) as cases and 50 normotensive pregnant women as controls from the Sampa Government Hospital, Ghana. We estimated for adrenomedullin (AM),calcitonin gene-related peptide (CGRP),soluble forms of intercellular adhesion molecule-1 (sICAM-1), Na+, K+, and Mg2+ before MgSO4 treatment, 24 h after MgSO4 treatment, and 48 h after delivery. p < 0.05 were considered significant for statistical analyses. Levels of AM, sICAM-1, and Na+ decreased significantly at 24 h after MgSO4 treatment and 48 h after delivery among PEwomen compared to the AM levels before treatment (p < 0.0001). The levels of CGRP and Mg2+ increased significantly after 24 h of MgSO4 treatment and 48 h after delivery among PE compared to the AM levels before treatment (p < 0.0001). The changes in AM, sICAM-1, CGRP, and Mg2+ at 24 h after treatment and 48 h after delivery were significantly higher in severe compared to mild PE (p < 0.0001). AM levels reduced significantly by 14.7% in mild and 42.7% in severe PE after MgSO₄ treatment (p < 0.05). sICAM-1 levels reduced significantly by 20.9% in mild and 25% in severe PE after MgSO₄ treatment. After MgSO₄ treatment, there was significant increase of 42.1% and >100% in CGRP levels in mild and severe PE, respectively (p < 0.05). After MgSO₄ treatment, Mg²⁺ levels increased significantly by 67.0% and 63.8% in mild and severe PE, respectively (p < 0.05). MgSO₄ treatment reduces AM, sICAM-1, and sodium levels but improves magnesium and CGRP in severe than mild PE thus have more beneficial role in severe PE.

Effect of moxibustion and scraping on bioactive substances changes of acupoints in knee osteoarthritis rats

To compare the effects of moxibustion and scraping of "Yanglingquan" (GB34) and "Xuehai" (SP10) area on changes of bioactive substances in the region of acupoints in rats with knee osteoarthritis (KOA). SD rats were randomly divided into blank, model, moxibustion, scraping, and moxibustion + scraping (combination) groups, with 8 rats in each group. The KOA model was established by injecting 50 μL 0.9% sodium chloride solution into the right knee cavity. Fourteen days after modeling, GB34 and SP10 on the right limb were stimulated by moxibustion (10 min) or scraping (till regional flush) once every other day for 7 times. The mechanical paw withdrawal threshold (PWT) and thermal withdrawal latency (TWL) were tested by Von Frey and hot stabbing instrument, separately. The pathological changes of the right knee joint were observed by HE staining. The serotonin (5-HT) contents of skin tissues in the region of acupoint GB34 and SP10 were detected by ELISA. The expression levels of substance P (SP) and calcitonin gene-related peptide (CGRP) in GB34 and SP10 region skin tissues were detected by Western blot. Compared with the blank group, the PWT and TWL of the rats in the model group were significantly decreased (P<0.001), while the contents of 5-HT and the expression levels of SP and CGRP in GB34 and SP10 region skin tissues were significantly increased (P<0.001, P<0.01). Following intervention and in comparison the with the model group, the TWL and PWT of rats in the three treatment groups were significantly increased (P<0.01), the content of 5-HT and the expression levels of SP and CGRP in GB34 and SP10 region skin tissues were significantly decreased (P<0.01, P<0.001, P<0.05). Except for the expression levels of CGRP, the above indexes of the combination group were significantly superior to those of the moxibustion and scraping groups (P<0.05, P<0.01). Findings of HE staining showed severe damaged cartilage, few chondrocytes on the surface, with subchondral neovascularization in the model group, which was relatively milder in the moxibustion, scraping, and combination groups. Moxibustion and scraping can relieve knee joint pain in KOA rats, which may be associated with its function in down-regulating the expression levels of SP and CGRP, and the content of 5-HT. The therapeutic effect of moxibustion plus scraping is better than that of moxibustion and scraping alone.

Calcitonin Gene-Related Peptide and Adrenomedullin Levels During Ictal and Interictal Periods in Patients With Migraine.

Background Peptides related to calcitonin gene-related peptide (CGRP) have been suggested to have a role in migraine. Adrenomedullin (AM) might be a candidate molecule because it is related to pain pathways in the peripheral and central nervous systems and uses the same receptors as CGRP. Methodology In this study, we examined the serum CGRP and AM levels during unprovoked ictal and interictal periods of 30 migraine patients as well as 25 healthy controls. Another focus of this study was on the association of CGRP and AM levels with clinical features. Results Mean serum AM levels were 15.80 pg/mL (11.91-21.43 pg/mL) in the ictal and 15.85pg/mL (12.25-19.29 pg/mL) in the interictal periods in the migraine group and 13.36pg/mL (10.84-17.18 pg/mL) in the control group. Mean serum CGRP levels were 2.93pg/mL (2.45-3.90 pg/mL) in the ictal and 3.25pg/mL (2.85-4.67 pg/mL) in the interictal periods in the migraine group and 3.03pg/mL (2.48-3.80 pg/mL) in the control group. There were no statistical differences between ictal and/or interictal AM and CGRP levels (p = 0.558 and p = 0.054, respectively) which were also comparable with the results of the control group (p = 0.230, p = 0.295, p = 0.987, p = 0.139, respectively). Ictal serum CGRP and/or AM levels did not correlate with any of the reported clinical features. Conclusions Serum AM and CGRP levels are similar in interictal and unprovoked ictal periods in migraine patients and as well in controls. These results do not indicate that these molecules do not have a role in migraine pathophysiology. Considering the broad mechanisms of action of peptides in the CGRP family, further studies are needed in larger cohorts.

Expression of neurotransmitters, vasculogenesis markers and myosin heavy chain isoforms in the masseter muscle of senescence-accelerated mouse prone 8 mice.

Learning and memory deficits and pathologic changes in the hippocampus caused by toothlessness and soft diet feeding are related to reduced masseter muscle (MM) function. Myosin heavy chain (MyHC) isoform expression in the MM also changes under different chewing conditions. The neurotransmitter calcitonin gene-related peptide (CGRP) and vascular endothelial growth factor A (VEGF-A) are involved in MM formation. However, the relationship between CGRP, VEGF-A and MyHC isoforms in the MM in the senescence-accelerated mouse prone 8 (SAMP8) strain, a model of learning and memory deficits, remains unclear. Changes in CGRP, VEGF-A, vasculogenesis marker, and MyHC isoform mRNA expression in the MMs of aging SAMP8 and senescence-accelerated mouse resistant 1 (SAMR1) mice was investigated through quantitative real-time polymerase chain reaction (qRT-PCR) and in situ hybridization. qRT-PCR revealed obviously high CGRP levels in the SAMP8 mouse MM (p<0.001). MyHC-IId/x mRNA expression in the MM was higher in 24-week-old SAMP8 mice than 24-week-old SAMR1 mice (p<0.001) but lower in slow-MyHC SAMP8 mice than SAMR1 mice (p<0.001). CGRP mRNA was observed on the muscle fibers of the SAMP8 mouse MM but not the SAMR1 mouse MM through in situ hybridization. Principal component analysis (PCA) revealed strong positive contributions of SAMP8-MyHC-IId/x, SAMP8-CGRP, SAMR1-MyHC-emb, SAMR1-CGRP, SAMR1-VEGF-A, SAMR1-CD31, SAMP8-VEGF-A, and SAMP8-CD31 in the MM at 12 and 24 weeks. CGRP is also key for the MyHC-IId/x and slow-MyHC patterns in the MMs of SAMP8 mice.

Evaluation of serum calcitonin gene related peptide (CGRP) Level in HIV infected patients as an indicator of disease activity

Human immunodeficiency virus (HIV) infection is under global attention due to its rapid spread and high rate of morbidity and mortality. HIV gets an access into the mucosa of genital epithelium through binding to Langerhans cells. While viral load and CD4+ cell count are the main parameters to detect disease activity, new biomarkers are introduced as a potential parameter for monitoring of disease activity in HIV infected patients. Calcitonin Gene Related Peptide (CGRP) is a neuropeptide that is secreted by peripheral neurons at genital epithelia and plays an important role in limitation of HIV transmission and spread to infected CD4+ cells through its effect onto Langerhans cells. This study aimed to evaluate the serum level of CGRP in HIV infected patients and to determine whether CGRP can serve as an indicator of HIV infection activity. The study included 104 HIV patients and 24 normal controls. Patients were divided into four groups. Serum levels of CGRP were measured by ELISA and correlated to viral load and CD4+ cells count for patients in the four groups: primary HIV infection (PHI), chronic HIV infection (CHI) before combinational antiretroviral therapy (cART-naïve), chronic HIV infection after one year of cART-initiation, and chronic HIV infection after two years of cART. Serum levels of CGRP were also measured in sera of controls and compared to patients' groups. Serum levels of CGRP were significantly lower in cART naïve PHI and CHI patients in comparison with normal controls (p < 0.05), Also, serum CGRP levels were positively correlated with CD4+ cells count (p < 0.01), but negatively correlated with viral load (p>0.05). In conclusion, CGRP could be proposed as an indicator of disease activity in HIV patients.

Activation of TRPV1-Expressing Renal Sensory Nerves of Rats with N-Oleoyldopamine Attenuates High-Fat-Diet-Induced Impairment of Renal Function.

Enhanced renal sympathetic nerve activity (RSNA) contributes to obesity-induced renal disease, while the role of afferent renal nerve activity (ARNA) is not fully understood. The present study tested the hypothesis that activating the transient receptor potential vanilloid 1 (TRPV1) channel in afferent renal nerves suppresses RSNA and prevents renal dysfunction and hypertension in obese rats. N-oleoyldopamine (OLDA, 1 ng/kg, daily) was administrated intrathecally (T8-L3) via an indwelled catheter to chronically activate, TRPV1-positive afferent renal nerves in rats fed a chow diet or high-fat diet (HFD) for 8 weeks. HFD intake significantly increased the body weight, impaired glucose and insulin tolerance, decreased creatinine clearance, and elevated systolic blood pressure in rats compared with the levels of the chow-fed rats (all p < 0.05). An intrathecal OLDA treatment for 8 weeks did not affect the fasting glucose level, glucose tolerance, and insulin tolerance in rats fed either chow or HFD. As expected, the chronic OLDA treatment significantly increased the levels of plasma calcitonin gene-related peptide and substance P and ARNA in the HFD-fed rats (all p < 0.05). Interestingly, the OLDA treatment decreased the urinary norepinephrine level and RSNA in rats fed HFD (both p < 0.05). Importantly, the OLDA treatment attenuated HFD-induced decreases in creatinine clearance and urinary Na+ excretion and increases in the plasma urea level, urinary albumin level, and systolic blood pressure at the end of an 8-week treatment (all p < 0.05). Taken together, the intrathecal administration of OLDA ameliorates the enhancement of RSNA, renal dysfunction, and hypertension in obese rats. These findings shed light on the roles of TRPV1-positive renal afferent nerves in obesity-related renal dysfunction and hypertension.

Electroacupuncture at Fengchi(GB20) and Yanglingquan(GB34) Ameliorates Paralgesia through Microglia-Mediated Neuroinflammation in a Rat Model of Migraine

Multiple studies have suggested that paralgesia (hyperalgesia and cutaneous allodynia) in migraine reflects the activation and sensitisation of the trigeminovascular system (TGVS). In particular, it reflects the second-order and higher nerve centre sensitisation, which is caused and maintained by neuroinflammation. Microglia activation leads to the release of proinflammatory cytokines involved in inflammatory responses. Accumulating evidence indicates that electroacupuncture (EA) is effective in ameliorating paralgesia, but the underlying mechanisms of EA in migraine attacks caused by microglia and microglia-mediated inflammatory responses are still unclear. The purpose of this study was to explore whether EA could ameliorate the dysregulation of pain sensation by suppressing microglial activation and the resulting neuroinflammatory response, and to evaluate whether this response was regulated by Toll-like receptor 4 (TLR4)/nuclear factor-kappa B(NF-κB) in the trigeminal nucleus caudalis (TNC) in a rat model of migraine. Repeated Inflammatory Soup (IS) was infused into the dura for seven sessions to establish a recurrent migraine-like rat model, and EA treatment was administered at Fengchi (GB20) and Yanglingquan (GB34) after daily IS infusion. Facial mechanical withdrawal thresholds were measured to evaluate the change in pain perception, and plasma samples and the TNC tissues of rats were collected to examine the changes in calcitonin gene-related peptide (CGRP), the Ibal-1-labelled microglial activation, and the resulting inflammatory response, including interleukin-1β (IL-1β), tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), and their regulatory molecules TLR4/NF-κB, via enzyme-linked immunosorbent assay (ELISA), real-time polymerase chain reaction (RT-PCR), immunohistochemistry (IHC) and Western blot analysis. Repeated IS injections into the dura induced facial mechanical paralgesia, which is the manifestation of migraine attacks, and increased the expression of CGRP, Ibal-1, microglial mediated inflammatory cytokines (IL-1β, TNF-α, IL-6), and regulatory molecules TLR4/NF-κB. EA at GB20/34 significantly attenuated repetitive IS-induced pain hypersensitivity. This effect was consistent with decreased levels of CGRP and inflammatory cytokines in the plasma and the TNC via the inhibition of microglia activation, and this response may be regulated by TLR4/NF-κB. EA ameliorated paralgesia in repetitive IS-induced migraine-like rats, which was mainly mediated by a reduction in microglial activation and microglial-mediated inflammatory responses that could be regulated by TLR4/NF-κB.

Hangover headache and its behavioral changes in rats.

The present study aims to establish and evaluate a rat model for hangover headaches caused by alcoholic drinks. Chronic migraine (CM) model rats were divided into 3 groups, and intragastrically administered alcoholic drinks (sample A, B, or C) to simulate hangover headache attacks. The withdrawal threshold for the hind paw/face and the thermal latency of hind paw withdrawal were detected after 24 hr. Serum was collected from the periorbital venous plexus of rats in each group, and enzymatic immunoassays were used to determine the serum levels of calcitonin gene-related peptide (CGRP), substance P (SP), and nitric oxide (NO). Compared with the control group, the mechanical hind paw pain threshold was significantly lower in rats administered Samples A and B after 24 hr; however, no significant difference was observed across groups for the thermal pain threshold. The mechanical threshold for periorbital pain was only significantly reduced in rats administered Sample A. Immunoassays further indicated that serum levels of SP in the group administered Sample A were significantly higher than those in the control group; the serum levels of NO and CGRP were significantly higher in the group of rats receiving Sample B. We successfully developed an effective and safe rat model for investigating alcohol drink induced hangover headaches. This model could be used to investigate the mechanisms associated with hangover headaches for the development of novel and promising candidates for the future treatment or prophylaxis of hangover headaches.

Sex Hormones and Calcitonin Gene-Related Peptide in Women With Migraine: A Cross-sectional, Matched Cohort Study.

Sex hormones may modulate calcitonin gene-related peptide (CGRP) release in the trigeminovascular system. We studied CGRP concentrations in plasma and tear fluid in female participants with episodic migraine (EM) and a regular menstrual cycle (RMC), female participants with EM and combined oral contraception (COC), and female participants with EM in the postmenopause. For control, we analyzed 3 corresponding groups of age-matched female participants without EM. Participants with an RMC had 2 visits: during menstruation on menstrual cycle day 2 ± 2 and in the periovulatory period on day 13 ± 2. Participants with COC were examined at day 4 ± 2 of the hormone-free interval (HFI) and between days 7 and 14 of hormone intake (HI). Postmenopausal participants were assessed once at a random time point. Plasma and tear fluid samples were collected at each visit for determination of CGRP levels with an ELISA. A total of 180 female participants (n = 30 per group) completed the study. Participants with migraine and an RMC showed statistically significantly higher CGRP concentrations in plasma and tear fluid during menstruation compared with female participants without migraine (plasma: 5.95 pg/mL [IQR 4.37-10.44] vs 4.61 pg/mL [IQR 2.83-6.92], p = 0.020 [Mann-Whitney U test]; tear fluid: 1.20 ng/mL [IQR 0.36-2.52] vs 0.4 ng/mL [IQR 0.14-1.22], p = 0.005 [Mann-Whitney U test]). In contrast, female participants with COC and in the postmenopause had similar CGRP levels in the migraine and the control groups. In migraine participants with an RMC, tear fluid but not plasma CGRP concentrations during menstruation were statistically significantly higher compared with migraine participants under COC (p = 0.015 vs HFI and p = 0.029 vs HI, Mann-Whitney U test). Different sex hormone profiles may influence CGRP concentrations in people, with current or past capacity to menstruate, with migraine. Measurement of CGRP in tear fluid was feasible and warrants further investigation.

Hemodynamic and neurobiological factors for the development of chronic pelvic pain in patients with pelvic venous disorder

ObjectiveThe study was aimed at the identification of hemodynamic and neurobiological factors for the development of chronic pelvic pain (CPP) in patients with pelvic venous disorder (PeVD) using ultrasound, radionuclide, and enzyme immunoassay methods. MethodsThis cohort study included 110 consecutive patients with PeVD and 20 healthy controls. Seventy patients with PeVD had symptoms (CPP in 100% of cases, discomfort in hypogastrium, dyspareunia, vulvar varices, and dysuria), and 40 were asymptomatic. Patients underwent clinical examination, duplex ultrasound study of the pelvic veins and lower extremities, and single-photon emission computed tomography of the pelvic veins with in vivo labeled red blood cells. The prevalence, duration, severity, and pattern of reflux in the pelvic veins, as well as the severity of pelvic venous congestion, were evaluated. Healthy controls underwent only clinical and duplex ultrasound examination. All 130 patients were assessed using enzyme immunoassays to determine plasma levels of calcitonin gene-related peptide (CGRP) and substance P (SP). ResultsSymptomatic patients with PeVD had a higher prevalence of reflux in the ovarian veins (OVs) than asymptomatic ones (45.7% vs 10%, respectively; P = .001) and a greater reflux duration (4.1 ± 1.7 seconds vs 1.4 ± 0.3 seconds; P = .002), although no differences in the OV diameter were found. Similar results were obtained when comparing the diameters of the parametrial veins (PVs) and the duration of reflux in them. Type II/III reflux (greater than 2 seconds) was identified in 41.4% of symptomatic and in only 5% of asymptomatic patients (P = .001). Among patients with CPP, 24.2% had a combined reflux in the OVs, PVs, and uterine veins, and 45.7% had a combined reflux in the OVs and PVs, whereas 90% of patients without CPP had only an isolated reflux in the PVs. The pelvic venous congestion was moderate or severe in 95.7% of patients with CPP and in only 15% patients without CPP (P = .001). In patients with PeVD, the presence of CPP was associated with higher levels of CGRP and SP compared with asymptomatic patients (CGRP: 0.48 ± 0.06 vs 0.19 ± 0.02 ng/mL, respectively, P = .001; SP: 0.38 ± 0.08 vs 0.13 ± 0.03 ng/mL, P = .001). ConclusionsIn patients with PeVD, significant hemodynamic and neurobiological factors for the CPP development were found to be reflux in the pelvic veins greater than 2 seconds, involvement of several venous collectors, and increased plasma levels of CGRP and SP.

High plasma calcitonin gene-related peptide and serum pituitary adenylate cyclase-activating polypeptide levels in patients with neuropathic pain

IntroductionBased on animal studies, calcitonin gene-related peptide (CGRP) and pituitary adenylate cyclase-activating polypeptide (PACAP) are thought to play a role in neurobiological events such as neuropathic pain, neuroprotection, neurotransmission, neural plasticity, and neurotrophic effects. The aim of the study is to investigate whether there is a change in the blood level of CGRP and PACAP in patients with neuropathic pain and to look for clues about the utility of these peptides as pharmacological targets in the treatment of neuropathic pain in humans. MethodsThe study included 60 polyneuropathy patients with neuropathic pain, 30 polyneuropathy patients without neuropathic pain (NNP) and 29 healthy subjects as control group. Polyneuropathy patients with neuropathic pain were divided into two groups as diabetic (D-PNP) and non-diabetic polyneuropathy (ND-PNP) patients. Plasma CGRP and serum PACAP levels were measured from venous blood samples of the patients and healthy controls. ResultsThe CGRP level was significantly higher in the D-PNP and ND-PNP groups compared to the control and NNP groups (P<0.05). PACAP levels were significantly higher in the D-PNP and ND-PNP groups compared to the control and NNP groups (P<0.05). There was no significant correlation between CGRP and PACAP levels and neuropathic pain scale (NPS). ConclusionsThis study is the first to demonstrate elevated plasma CGRP and serum PACAP levels in polyneuropathy patients with neuropathic pain. The results of this study are important in terms of showing that both CGRP and PACAP can be new pharmacological targets in the treatment of neuropathic pain and polyneuropathy in humans.

Human salivary concentrations of brain derived neurotrophic factor correlates with subjective pain intensity associated with initial orthodontic therapy

Current study aimed to evaluate presence & concentration of salivary molecular pain biomarkers Calcitonin Gene Related Peptide (CGRP) and Brain-Derived Neurotrophic Factor (BDNF) during initial stages of orthodontic treatment and correlation with subjective pain scales, Numerical Rating Scale (NRS), Visual Analogue Scale (VAS), Verbal Rating Scale (VRS) and McGill Pain Questionnaire (MPQ). Consented, healthy-pain free patients (n = 40) undergoing orthodontic therapy, having moderate crowding with pre-molar extraction were recruited. Unstimulated whole saliva was collected and stored at -80 °C in cryotubes. Levels of CGRP & BDNF in salivary samples was assessed by enzyme–linked immunosorbent assay. Samples were collected under stipulated 5 time periods using saliva collection tube by passive drooling method: immediately after bonding but before wire placement (T0-baseline), after 24 h (T1), 48 h (T2), 72 h (T3) & 168 h (T4) after wire placement. Consolidated subjective pain scales were administered concurrently. Regression value (R2 > 0.9) confirmed BDNF & CGRP in saliva. Significant change was observed from baseline to 168 h in all subjective parameters (p < 0.05). CGRP did not correlate with subjective pain scales statistically (p > 0.05). BDNF levels correlated with all the subjective pain scales, NRS (T3-p = 0.0092&T4-p = 0.0064), VRS (T3-p = 0.0112&T4-p = 0.0500), VAS (T3-p = 0.0092 &T4-p = 0.0064) &MPQ (T1-p = 0.0255). Mean BDNF & median subjective pain scale graphs were similar. BDNF correlated with all the subjective pain scales warranting further investigation.Trial registration; Clinical Trial Registry—India (CTRI) Reg No: CTRI/2018/12/016571; Registered 10th December, 2018 (10/12/2018) prospectively; http://ctri.nic.in/Clinicaltrials/pmaindet2.php?trialid=29640&EncHid=&userName=Dr%20Sagar%20S%20Bhat.

Qixue Shuangbu decoction and acupuncture combined with Western medicine in acute severe stroke patients.

Stroke is a common and frequently occurring disease of the nervous system and one of the three major diseases leading to human death. The incidence and mortality of stroke in China increase with age. Overall, 70 % of patients with stroke have serious disability, which results in heavy burden to their families and the society. To analyze the effects of Qixue Shuangbu decoction and acupuncture combined with Western medicine on immune indexes and digestive tract function in patients with acute severe stroke. A total of 68 patients with acute severe stroke admitted to Lanzhou Second People's Hospital between March 2018 and September 2021 were selected and divided into the control and observation groups according to a random number table method. The control group was administered routine Western medicine treatment, such as dehydration, lowering intracranial pressure, anticoagulation, improving cerebral blood circulation and cerebral nerve protection according to the "Guidelines for the Diagnosis and Treatment of Acute Ischemic Stroke in China." The observation group was administered Qixue Shuangbu decoction via nasal feeding tube on the basis of the routine Western medicine treatment with simultaneous acupuncture. The two groups were compared. The acute physiology and chronic health evaluation II, organ dysfunction syndrome score, National Institutes of Health Stroke Scale, and traditional Chinese medicine syndrome scores of the two groups were significantly decreased compared with those measured before treatment, and the complements C3 and C4, and immunoglobulins (Ig) M and G were significantly increased compared with those observed before treatment (P < 0.05). After treatment, the scores of the observation group were lower than those of the control group, and the complement and Ig levels were higher than those of the control group (P < 0.05). The levels of diamine oxidase (DAO), D-lactic acid (D-LA), and calcitonin gene-related peptide (CGRP) in the two groups were significantly higher than those before treatment, while the levels of lipopolysaccharide, ubiquitin carboxyl-terminal hydrolase 1 (UCH-L1), tumor necrosis factor-α (TNF-α), interleukin (IL) -2, and IL-8 were significantly lower than those before treatment (P < 0.05). After treatment, DAO, D-LA, and CGRP were higher in the observation group than in the control group, while lipopolysaccharide, UCH-L1, TNF-α, IL-2, and IL-8 were lower than in the control group (P < 0.05). The hospitalization time of individuals in the observation group was shorter than that of the control group (P < 0.05). Qixue Shuangbu decoction and acupuncture combined with Western medicine for the treatment of acute severe stroke can regulate intestinal flora, reduce inflammation, improve intestinal mucosal barrier function and immune function related indicators, and promote recovery.

Calcitonin gene-related peptide ameliorates sepsis-induced intestinal injury by suppressing NLRP3 inflammasome activation

Intestinal damage has long been viewed as the primary cause of sepsis-induced multiple organ dysfunction syndrome (MODS). Previous studies have demonstrated that calcitonin gene-related peptide (CGRP) exhibits anti-inflammatory and protective effects in mice exposed to endotoxin. This study investigated whether CGRP protects against sepsis-induced intestinal damage and its underlying mechanisms. Using a murine caecal ligation and puncture (CLP) model, we observed elevated serum and intestinal CGRP levels in septic mice. CGRP knockout (KO) mice showed more severe intestinal barrier damage, excessive NLRP3 inflammasome activation and higher levels of inflammation. In vitro, we used lipopolysaccharide (LPS) and adenosine triphosphate (ATP) to activate the NLRP3 inflammasome in MODE-K murine intestinal epithelial cells. CGRP inhibited NF-κB pathway activation; prevented ASC assembly and ROS accumulation; significantly decreased NLRP3, Caspase-1 p10, and IL-1β levels and LDH release; and increased cell viability. Treatment with an IL-1β inhibitor or CGRP suppressed p38 MAPK and ERK1/2 pathway activation and increased ZO-1 and Occludin protein levels in LPS+ATP-treated MODE-K cells. Finally, we used the CGRP upstream agonist drug rutaecarpine (RUT) to control endogenous CGRP release in mice, and this drug demonstrated good therapeutic effects on septic intestinal injury. In conclusion, our results suggest that CGRP ameliorates sepsis-induced intestinal damage, providing valuable insights for drug development.