scholarly journals Electroacupuncture Stimulation Alleviates CFA-Induced Inflammatory Pain Via Suppressing P2X3 Expression

2019 ◽  
Vol 20 (13) ◽  
pp. 3248 ◽  
Author(s):  
Xuaner Xiang ◽  
Sisi Wang ◽  
Fangbing Shao ◽  
Junfan Fang ◽  
Yingling Xu ◽  
...  
Keyword(s):  
Inflammatory Pain ◽  
Analgesic Effect ◽  
Purinergic Receptor ◽  
Pathological Process ◽  
Spinal Cord Dorsal Horn ◽  
Chronic Inflammatory Pain ◽  
Withdrawal Threshold ◽  
Analgesic Effects ◽  
Spinal Cord Dorsal

Chronic inflammatory pain is one of the most common complaints that seriously affects patients’ quality of life. Previous studies have demonstrated that the analgesic effect of electroacupuncture (EA) stimulation on inflammatory pain is related to its frequency. In this study, we focused on whether the analgesic effects of EA are related to the period of stimulation. Purinergic receptor P2X3 (P2X3) is involved in the pathological process underlying chronic inflammatory pain and neuropathic pain. We hypothesized that 100 Hz EA stimulation alleviated Freund’s complete adjuvant (CFA) induced inflammatory pain via regulating P2X3 expression in the dorsal root ganglion (DRG) and/or spinal cord dorsal horn (SCDH). We also assumed that the analgesic effect of EA might be related to the period of stimulation. We found that both short-term (three day) and long-term (14 day) 100 Hz EA stimulation effectively increased the paw withdrawal threshold (PWT) and reversed the elevation of P2X3 in the DRG and SCDH of CFA rats. However, the analgesic effects of 100 Hz EA were not dependent on the period of stimulation. Moreover, P2X3 inhibition or activation may contribute to or attenuate the analgesic effects of 100 Hz EA on CFA-induced inflammatory pain. This result indicated that EA reduced pain hypersensitivity through P2X3 modulation.

scholarly journals Electroacupuncture Inhibits the Activation of p38MAPK in the Central Descending Facilitatory Pathway in Rats with Inflammatory Pain

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Man-Li Hu ◽  
Fei-Yan Zhou ◽  
Jing-Jing Liu ◽  
Yi Ding ◽  
Ju-Ming Zhong ◽  
...  
Keyword(s):  
Inflammatory Pain ◽  
Spinal Cord Dorsal Horn ◽  
Rostral Ventromedial Medulla ◽  
Saline Injection ◽  
Paw Edema ◽  
Pain Model ◽  
Withdrawal Threshold ◽  
Ventromedial Medulla ◽  
Mitogen Activated Protein ◽  
Spinal Cord Dorsal

The mitogen-activated protein kinases (MAPKs), especially p38MAPK, play a pivotal role in chronic pain. Electroacupuncture (EA) relieves inflammatory pain underlying the descending pathway, that is, the periaqueductal gray (PAG), the rostral ventromedial medulla (RVM), and the spinal cord dorsal horn (SCDH). However, whether EA antagonizes inflammatory pain through regulation of p38MAPK in this descending facilitatory pathway is unclear. Complete Freund’s adjuvant (CFA) was injected into the hind paw of rats to establish inflammatory pain model. EA was administrated for 30 min at Zusanli and Kunlun acupoints at 0.5, 24.5, 48.5, and 72.5 h, respectively. The paw withdrawal threshold (PWT), paw edema, and Phosphor-p38MAPK-Immunoreactivity (p-p38MAPK-IR) cells were measured before (0 h) and at 1, 3, 5, 7, 25, and 73 h after CFA or saline injection. EA increased PWT at 1, 3, 25, and 73 h and inhibited paw edema at 25 and 73 h after CFA injection. Moreover, the increasing number of p-p38MAPK-IR cells which was induced by CFA was suppressed by EA stimulation in PAG and RVM at 3 and 5 h and in SCDH at 5, 7, 25, and 73 h. These results suggest that EA suppresses inflammation-induced hyperalgesia probably through inhibiting p38MAPK activation in the descending facilitatory pathway.

scholarly journals Galanin Receptor 2 Is Involved in Galanin-Induced Analgesic Effect by Activating PKC and CaMKII in the Nucleus Accumbens of Inflammatory Pain Rats

2021 ◽  
Vol 14 ◽  
Author(s):  
Mengnan Li ◽  
Xiaomin Zhang ◽  
Chongyang Li ◽  
Yanan Liu ◽  
Shuang Yang ◽  
...  
Keyword(s):  
Nucleus Accumbens ◽  
Protein Kinase ◽  
Inflammatory Pain ◽  
Analgesic Effect ◽  
Signaling Mechanism ◽  
Withdrawal Threshold ◽  
Calcium Calmodulin Dependent ◽  
Kinase C ◽  
Dependent Protein ◽  
Galanin Receptors

It has been reported that galanin has an analgesic effect via activating galanin receptors (GALRs). This study focused on the involvement of GALR2 in the galanin-induced analgesic effect and its signaling mechanism in the nucleus accumbens (NAc) of inflammatory rats. Animal models were established through injecting carrageenan into the plantar of rats’ left hind paw. The results showed that GALR2 antagonist M871 weakened partially the galanin-induced increases in hind paw withdrawal latency (HWL) to thermal stimulation and hind paw withdrawal threshold (HWT) to mechanical stimulation in NAc of inflammatory rats. Moreover, the GALR2 agonist M1145 prolonged the HWL and HWT, while M871 blocked the M1145-induced increases in HWL and HWT. Western blotting showed that the phosphorylation of calcium/calmodulin-dependent protein kinase II (p-CaMKII) and protein kinase C (p-PKC) in NAc were upregulated after carrageenan injection, while p-PKC and p-CaMKII were downregulated after intra-NAc administration of M871. Furthermore, the CaMKII inhibitor KN93 and PKC inhibitor GO6983 attenuated M1145-induced increases in HWL and HWT in NAc of rats with inflammatory pain. These results prove that GALR2 is involved in the galanin-induced analgesic effect by activating CaMKII and PKC in NAc of inflammatory pain rats, implying that GALR2 agonists probably are potent therapeutic options for inflammatory pain.

scholarly journals Analgesic Effect of Moxibustion with Different Temperature on Inflammatory and Neuropathic Pain Mice: A Comparative Study

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Wei Zhou ◽  
Ruxue Lei ◽  
Chuanyi Zuo ◽  
Yunqing Yue ◽  
Qin Luo ◽  
...  
Keyword(s):  
Neuropathic Pain ◽  
Inflammatory Pain ◽  
Analgesic Effect ◽  
Mechanical Allodynia ◽  
Thermal Hyperalgesia ◽  
Spared Nerve Injury ◽  
Chronic Neuropathic Pain ◽  
Chronic Inflammatory Pain ◽  
Significant Difference ◽  
Different Temperatures

The aim of this study was to determine whether variation of temperature during moxibustion would generate division of analgesic effect. The moxibustion with different temperatures (37°C, 42°C, 47°C, and 52°C) was applied to ST36 acupoint for 30 minutes in chronic inflammatory or neuropathic pain mice. The analgesic effect was evaluated by thermal hyperalgesia test in chronic inflammatory pain and by mechanical allodynia in neuropathic pain, respectively. The results indicated that interventions of moxibustion with different temperature caused different analgesic effect on either chronic inflammatory induced by injection of complete Freund’s adjuvant (CFA) or neuropathic pain induced by spared nerve injury (SNI). In chronic inflammatory pain, different moxibustion temperature generated different intensity of analgesic effect: the higher the better. In chronic neuropathic pain, stronger analgesic effect was found in moxibustion with temperature 47°C or 52°C other than 37°C and 42°C. However, there is no significant difference displayed between moxibustion temperatures 47°C and 52°C or 37°C and 42°C. It implies that the temperature should be taken into account for moxibustion treatment to chronic inflammatory or neuropathic pain.

scholarly journals The Analgesic Effects of Celecoxib on the Formalin-induced Short- and Long-term Inflammatory Pain

2017 ◽  
Vol 4 (20;4) ◽  
pp. E575-584 ◽  
Author(s):  
Ya-Qun Zhao
Keyword(s):  
Inflammatory Pain ◽  
Formalin Test ◽  
Formalin Injection ◽  
Spontaneous Pain ◽  
Second Phase ◽  
Secondary Hyperalgesia ◽  
Analgesic Effects ◽  
Gastrointestinal Side Effects ◽  
Short And Long Term

The non-steroidal anti-inflammatory drug celecoxib has long been used for reducing pain, in spite of moderate gastrointestinal side effects. In previous studies, it has been shown that celecoxib can inhibit formalin-induced spontaneous pain and secondary hyperalgesia. Injecting formalin into a rodent’s hind paw not only induces acute pain behaviors, but also produces long-lasting hyperalgesia. Whether celecoxib can also have long-lasting effects is still unknown. Our results show that pretreatment with an intraperitoneal injection of celecoxib at one hour before formalin injection induced inhibition on the spontaneous flinch and licking behaviors in the second phase but not the first phase. Meanwhile, FOS expressions were also reduced with celecoxib pretreatment. Consecutive administration of celecoxib also protects the hind paw from hypoalgesia and relieves formalininduced, long-lasting hyperalgesia in the ipsilateral hind paw. These analgesic effects may be related to suppression of the activation of neurons and astrocytes indicated by FOS and GFAP expressions. Based on the above findings, celecoxib demonstrated analgesic effects not only on acute spontaneous pain behavior but also on long-lasting hyperalgesia induced by formalin injection. The inhibition of neurons and astrocytes by celecoxib may be possible reasons for its analgesia. Key words: Formalin test, celecoxib, FOS, GFAP, hyperalgesia

scholarly journals High Frequency Repetitive Transcranial Magnetic Stimulation Therapy For Chronic Neuropathic Pain: A Meta-analysis

2015 ◽  
Vol 6;18 (6;11) ◽  
pp. E1029-E1046 ◽  
Author(s):  
Qiwen Mu
Keyword(s):  
Neuropathic Pain ◽  
Transcranial Magnetic Stimulation ◽  
High Frequency ◽  
Analgesic Effect ◽  
Magnetic Stimulation ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Meta Analysis ◽  
Optimal Parameters ◽  
Analgesic Effects

Background: Increasing evidence supports an analgesic effect of repetitive transcranial magnetic stimulation (rTMS) for neuropathic pain (NP). However, the optimal parameters of rTMS (stimulation frequency and treatment sessions) for achieving long-term analgesic effects remain unknown. This study analyzed the current findings in the literature. Objective: The aim of this study was to assess the optimal parameters of rTMS for NP, including the rTMS sessions needed for inducing acute as well as long-term analgesic effects. Study Design: A meta-analysis of the analgesic effect of high frequency rTMS (HF- rTMS) for neuropathic patients. Setting: This meta-analysis examined all studies involving the analgesic efficacy of HF-rTMS for NP. Methods: PubMed, Embase, and the Cochrane library were searched for clinical studies of rTMS treatment on NP published before December 31, 2014. Crude standardized mean differences (SMD) with 95% confidence interval (CI) were calculated for pain intensity after different treatment sessions (from 1 to 10) and follow-up of one or 2 months after rTMS treatment using random effect models. Results: Twenty-five studies (including 32 trials and 589 patients) were selected for the metaanalysis according to the inclusion and exclusion criteria. All 3 HF-rTMS treatments (5, 10, and 20 Hz) produced pain reduction, while there were no differences between them, with the maximal pain reduction found after one and 5 sessions of rTMS treatment. Further, this significant analgesic effect remained forone month after 5 sessions of rTMS treatment. Limitations: There are limitations of this meta-analysis. For example, the long-term analgesic effects of different HF-rTMS and low frequency (LF) rTMS sessions, including the single session of rTMS on different NP of varying origins have yet not been evaluated; the full degree of pain relief is still unclear for many rTMS studies. Conclusions: HF-rTMS stimulation on primary motor cortex is effective in relieving pain in NP patients. Although 5 sessions of rTMS treatment produced a maximal analgesic effect and may be maintained for at least one month, further large-scale and well-controlled trials are needed to determine if this enhanced effect is specific to certain types of NP such as post-stroke related central NP. Key words: High frequency, repetitive transcranial magnetic stimulation, neuropathic pain, single stimulation, multiple stimulation, meta-analysis

scholarly journals Interferon-β suppresses inflammatory pain through activating µ-opioid receptor

2021 ◽  
Vol 17 ◽  
pp. 174480692110452
Author(s):  
Chien Cheng Liu ◽  
I Cheng Lu ◽  
Li Kai Wang ◽  
Jen Yin Chen ◽  
Yu Yu Li ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Western Blot ◽  
Opioid Receptor ◽  
Opioid Receptors ◽  
Inflammatory Pain ◽  
Analgesic Effect ◽  
Intrathecal Injection ◽  
Type I ◽  
Withdrawal Threshold ◽  
Withdrawal Latency

Interferons (IFNs) are cytokines secreted by infected cells that can interfere with viral replication. Besides activating antiviral defenses, type I IFNs also exhibit diverse biological functions. IFN-β has been shown to have a protective effect against neurotoxic and inflammatory insults on neurons. Therefore, we aimed to investigate the possible role of IFN-β in reducing mechanical allodynia caused by Complete Freund’s Adjuvant (CFA) injection in rats. We assessed the antinociceptive effect of intrathecal IFN-β in naïve rats and the rats with CFA–induced inflammatory pain. After the behavioral test, the spinal cords of the rats were harvested for western blot and immunohistochemical double staining. We found that intrathecal administration of IFN-β in naïve rats can significantly increase the paw withdrawal threshold and paw withdrawal latency. Further, the intrathecal injection of a neutralizing IFN-β antibody can reduce the paw withdrawal threshold and paw withdrawal latency, suggesting that IFN-β is produced in the spinal cord in normal conditions and serves as a tonic inhibitor of pain. In addition, intrathecal injection of IFN-β at dosages from 1000 U to 10000 U demonstrates a significant transient dose-dependent inhibition of CFA-induced inflammatory pain. This analgesic effect is reversed by intrathecal naloxone, suggesting that IFN-β produces an analgesic effect through central opioid receptor-mediated signaling. Increased expression of phospho-µ-opioid receptors after IFN-β injection was observed on western blot, and immunohistochemical staining showed that µ-opioids co-localized with IFN-α/βR in the dorsal horn of the spinal cord. The findings of this study demonstrate that the analgesic effect of IFN-β is through µ-opioid receptors activation in spial cord.

scholarly journals The analgesic effect of refeeding on acute and chronic inflammatory pain

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jeong-Yun Lee ◽  
Grace J. Lee ◽  
Pa Reum Lee ◽  
Chan Hee Won ◽  
Doyun Kim ◽  
...  
Keyword(s):  
Receptor Antagonist ◽  
Inflammatory Pain ◽  
Analgesic Effect ◽  
Cannabinoid Receptor ◽  
Pain Behavior ◽  
Spontaneous Pain ◽  
Second Phase ◽  
Pain Model ◽  
Chronic Inflammatory Pain ◽  
Effect Of Food

AbstractPain is susceptible to various cognitive factors. Suppression of pain by hunger is well known, but the effect of food intake after fasting (i.e. refeeding) on pain remains unknown. In the present study, we examined whether inflammatory pain behavior is affected by 24 h fasting and 2 h refeeding. In formalin-induced acute inflammatory pain model, fasting suppressed pain behavior only in the second phase and the analgesic effect was also observed after refeeding. Furthermore, in Complete Freund’s adjuvant-induced chronic inflammatory pain model, both fasting and refeeding reduced spontaneous pain response. Refeeding with non-calorie agar produced an analgesic effect. Besides, intraperitoneal (i.p.) administration of glucose after fasting, which mimics calorie recovery following refeeding, induced analgesic effect. Administration of opioid receptor antagonist (naloxone, i.p.) and cannabinoid receptor antagonist (SR 141716, i.p.) reversed fasting-induced analgesia, but did not affect refeeding-induced analgesia in acute inflammatory pain model. Taken together, our results show that refeeding produce analgesia in inflammatory pain condition, which is associated with eating behavior and calorie recovery effect.

Analgesic Effect of Methane Rich Saline in a Rat Model of Chronic Inflammatory Pain

2018 ◽  
Vol 43 (4) ◽  
pp. 869-877 ◽  
Author(s):  
Shu-Zhuan Zhou ◽  
Ya-Lan Zhou ◽  
Feng Ji ◽  
Hao-Ling Li ◽  
Hu Lv ◽  
...  
Keyword(s):  
Rat Model ◽  
Inflammatory Pain ◽  
Analgesic Effect ◽  
Chronic Inflammatory Pain
Sign in / Sign up

Export Citation Format

Share Document