scholarly journals Role of dopaminergic system in oxytocin analgesia: The missing part in a puzzle

2020 ◽  
Vol 19 (5) ◽  
pp. 1087-1092
Author(s):  
Yaşar Taştemur ◽  
Ahmet Şevki Taşkıran ◽  
Ahmet Altun ◽  
Ahmet Kemal Filiz ◽  
Kader Gülmez ◽  
...  

Purpose: To investigate the analgesic effects of oxytocin (OT) and elucidate the role of dopaminergic system in its mechanisms.Methods: In this study, 72 male (n=6 for each group) 230-250 gr Wistar Albino rats were used. Firstly, dose studies were performed with 100 μg/kg, 200 μg/kg and 400 μg/kg to determine the optimal analgesic effect of oxytocin. Optimal dose was found at 200 μg/kg, and then animals were divided into nine groups: Saline, D1 agonist (SKF 38393; 0.1 mg/kg), D1 antagonist (SCH-23390; 0.1 mg/kg), D1 agonist + oxytocin, D1 antagonist + oxytocin, D2 agonist (Cabergoline; 0,5 mg/kg), D2 antagonist (Sulpride; 10 mg/kg), D2 agonist + oxytocin and D2 antagonist + oxytocin. Serum physiologic saline was given to the saline group and other drugs were administered intraperitoneally at the indicated doses. Tail-flick and hot-plate tests were used to measure analgesic effects. Analgesic tests were measured in 30 min-intervals (at 30th, 60th, 90th, and 120th min) and recorded in seconds. To evaluate maximum antinociceptive effect (% MPE), the tail-flick and hot-plate latencies were converted to the antinociceptive effectivenessResults: The results show that D1 antagonist SCH-23390 (0.1 mg/kg) and D2 agonist cabergoline (0.5 mg/kg) created strong analgesia while the D1 agonist SKF 38393 (0.1 mg/kg) and D2 antagonist sulpiride (10 mg/kg) did not have any analgesic effect. However, only D2 antagonist sulpiride blocked the analgesic effect produced by OTConclusion: OT may be one of the primary agents participating in spinal analgesia, and the dopaminergic system is one of the central mechanisms of action for this important molecule. The dopaminergic system may also be one of the targets for ‘descending’ analgesic system. Keywords: Oxytocin, Tail flick, Hot plate, Dopaminergic, Analgesic, Antagonist, Agonist

2019 ◽  
Vol 65 (3) ◽  
pp. 22-31
Author(s):  
Ighodaro Igbe ◽  
Osaze Edosuyi ◽  
Agbonlahor Okhuarobo ◽  
Adarki Pongri ◽  
Nkechi Maduako ◽  
...  

Summary Introduction: Potato (Solanum tuberosum L.) is an important vegetable crop in Syria. Potato tuber moth Cussonia barteri is a small tree that grows in the sub-Saharan part of Africa. Various parts of the plant are used for the treatment of a variety of ailments in ethno-medicine. Objective: To evaluate the anti-inflammatory and analgesic effect of the methanol leaf extract of Cussonia barteri. Material and methods: The leaves were air-dried, powdered and repeatedly extracted with methanol using a Soxhlet apparatus. The resulting methanol extract (100, 200 and 400 mg/kg) was evaluated for anti-inflammatory activity using carrageenan-induced paw oedema, xylene-induced ear oedema and formalin-induced arthritis tests. Analgesic effect was evaluated using acetic acid-induced mouse writhing, hot plate and tail flick tests. Results: All doses of the extract significantly (p<0.05) reduced carrageenan-induced paw oedema, however the 400 mg/kg dose gave a sustained effect. The extract significantly inhibited xylene induced ear oedema at all doses. There were no significant (p>0.05) reductions in paw swellings due to formalin. In the acetic acid induced writhing test, the extract significantly (p<0.05) decreased writhing at 400 mg/kg only. Reaction times were not significantly different from the control in the hot plate and tail flick tests. Conclusion: This study has shown that the methanol extract possesses acute anti-inflammatory and peripherally mediated analgesic effects.


Author(s):  
Osaze Edosuyi ◽  
Ighodaro Igbe ◽  
Loretta Oghenekome Iniaghe

AbstractBackground(HU) (K. Schum) is used in ethnomedicine for the management of pain, diabetes mellitus and dysmenorrhoea. This study evaluated the analgesic and antioxidant activities of aqueous extract of HU stem bark and the possible mechanism(s) of action.MethodsThe antinociceptive effect of HU was evaluated using acetic acid mouse writhing, tail flick, hot plate and formalin-induced paw licking models. To establish the possible mechanism(s) of action of HU, separate group of animals were pretreated with naloxone (1 mg/kg, i.p.), atropine (1 mg/kg, i.p.), haloperidol (0.1 mg/kg, i.p.), ondansetron (1 mg/kg, i.p.) and phenoxybenzamine (0.1 mg/kg, i.p.), 15 min before HU. TheResultsThe extract at 150 and 300 mg/kg, significantly (pConclusionsResults obtained in this study suggest the involvement of serotonergic, opioidergic and dopaminergic pathways in the analgesic effect of HU stem bark, in addition to its potent antioxidant potential.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Gao Wu ◽  
Hanbin Wu

Objective. To evaluate the synergistic analgesic effect of essential oil ofZanthoxylum schinifoliumSieb. et Zucc. (EOZ) and verapamil (Ver).Method. The qualitative and quantitative composition of EOZ were determined with gas chromatography/Mass spectrometer. The interaction between EOZ and Ver in antinociceptive activity was evaluated by using acetic acid-induced writhing, hot plate, and tail flick tests in mice and in isolated toad sciatic nerve test.Results. Linalool, limonene, and sabinene are the major components of EOZ. EOZ (middle-dose: 40 mg·kg−1, high-dose: 80 mg·kg−1) and EOZ + Ver (Each dose group) have remarkable analgesic effects on pain in mice induced by acetic acid-induced writhing, hot plate, and tail flick tests. Low-dose EOZ (20 mg·kg−1) had no analgesic action, but when it is combined with Ver it has shown significant antinociception. Verapamil has a faint analgesic effect but was not able to inhibit action potential transmission in toad sciatic nerve. EOZ (0.2%) and EOZ + Ver (0.2% + 0.05%) also inhibited action potential transmission in toad sciatic nerve. Combination of EOZ with Ver had a greater analgesic effect and inhibition of nerve action potential transmission compared to its components EOZ and Ver.Conclusion. The combination of EOZ with Ver produces a synergistic analgesic effect.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Ioana-Mirela Vasincu ◽  
Maria Apotrosoaei ◽  
Sandra Constantin ◽  
Maria Butnaru ◽  
Liliana Vereștiuc ◽  
...  

Abstract Background Aryl-propionic acid derivatives with ibuprofen as representative drug are very important for therapy, being recommended especially for anti-inflammatory and analgesic effects. On other hand 1,3-thiazolidine-4-one scaffold is an important heterocycle, which is associated with different biological effects such as anti-inflammatory and analgesic, antioxidant, antiviral, antiproliferative, antimicrobial etc. The present study aimed to evaluated the toxicity degree and the anti-inflammatory and analgesic effects of new 1,3-thiazolidine-4-one derivatives of ibuprofen. Methods For evaluation the toxicity degree, cell viability assay using MTT method and acute toxicity assay on rats were applied. The carrageenan-induced paw-edema in rat was used for evaluation of the anti-inflammatory effect while for analgesic effect the tail-flick test, as thermal nociception in rats and the writhing assay, as visceral pain in mice, were used. Results The toxicological screening, in terms of cytotoxicity and toxicity degree on mice, revealed that the ibuprofen derivatives (4a-n) are non-cytotoxic at 2 μg/ml. In addition, ibuprofen derivatives reduced carrageenan-induced paw edema in rats, for most of them the maximum effect was recorded at 4 h after administration which means they have medium action latency, similar to that of ibuprofen. Moreover, for compound 4d the effect was higher than that of ibuprofen, even after 24 h of administration. The analgesic effect evaluation highlighted that 4 h showed increased pain inhibition in reference to ibuprofen in thermal (tail-flick assay) and visceral (writhing assay) nociception models. Conclusions The study revealed for ibuprofen derivatives, noted as 4 m, 4 k, 4e, 4d, a good anti-inflammatory and analgesic effect and also a safer profile compared with ibuprofen. These findings could suggest the promising potential use of them in the treatment of inflammatory pain conditions.


Pharmacology ◽  
2011 ◽  
Vol 88 (5-6) ◽  
pp. 233-241 ◽  
Author(s):  
Shridhar V. Andurkar ◽  
Anil Gulati

2011 ◽  
Vol 89 (2) ◽  
pp. 89-95 ◽  
Author(s):  
Ercan Ozdemir ◽  
Ihsan Bagcivan ◽  
Nedim Durmus ◽  
Ahmet Altun ◽  
Sinan Gursoy

Although the phenomenon of opioid tolerance has been widely investigated, neither opioid nor nonopioid mechanisms are completely understood. The aim of the present study was to investigate the role of the nitric oxide (NO)–cyclic guanosine monophosphate (cGMP) pathway in the development of morphine-induced analgesia tolerance. The study was carried out on male Wistar albino rats (weighing 180–210 g; n = 126). To develop morphine tolerance, animals were given morphine (50 mg/kg; s.c.) once daily for 3 days. After the last dose of morphine was injected on day 4, morphine tolerance was evaluated. The analgesic effects of 3-(5′-hydroxymethyl-2′-furyl)-1-benzylindazole (YC-1), BAY 41-2272, S-nitroso-N-acetylpenicillamine (SNAP), NG-nitro-l-arginine methyl ester (L-NAME), and morphine were considered at 15 or 30 min intervals (0, 15, 30, 60, 90, and 120 min) by tail-flick and hot-plate analgesia tests (n = 6 in each study group). The results showed that YC-1 and BAY 41-2272, a NO-independent activator of soluble guanylate cyclase (sGC), significantly increased the development and expression of morphine tolerance, and L-NAME, a NO synthase (NOS) inhibitor, significantly decreased the development of morphine tolerance. In conclusion, these data demonstrate that the nitric oxide–cGMP signal pathway plays a pivotal role in developing tolerance to the analgesic effect of morphine.


2011 ◽  
Vol 02 (02) ◽  
pp. 130-136 ◽  
Author(s):  
Keshab Raj Paudel ◽  
SK Bhattacharya ◽  
GP Rauniar ◽  
BP Das

ABSTRACT Introduction: Newer anticonvulsants have a neuromodulatory effect on pain perception mechanisms in a hyperexcitable and damaged nervous system. Aim: This study was designed to study the analgesic effects of gabapentin alone and in combination with lamotrigine and topiramate in experimental pain models. Materials and Methods: Adult albino mice (n = 490) weighing 20–30 g and rats (n = 130) weighing 100–200 g were injected intraperitoneally with gabapentin, lamotrigine, and topiramate alone and in different dose combinations. The hot-plate method, tail-flick method, capsaicin-induced mechanical hyperalgesia, and formalin assay were used to assess the antinociceptive effects. Results: Of the three antiepileptic drugs, when given separately, gabapentin was more efficacious than either topiramate or lamotrigine in all the pain models. Combination of 25 mg/kg gabapentin with 25 mg/kg topiramate was more efficacious (P <.05) than 50 mg/kg gabapentin alone in the capsaicin-induced mechanical hyperalgesia test. Similarly, 50 mg/kg gabapentin with 50 mg/kg topiramate or 5 mg/kg lamotrigine was more efficacious (P <.05) than 50 or 100 mg/kg gabapentin alone in late-phase formalin-induced behaviors. Conclusions: Combination of gabapentin with either lamotrigine or topiramate produced better results than gabapentin alone in capsaicin-induced mechanical hyperalgesia test and in late-phase formalin-induced behaviors.


Author(s):  
Kartik Salwe J ◽  
Mirunalini R ◽  
Jervin Mano ◽  
Manimekalai K

 Objective: The objective of the study was to investigate the analgesic activity of hydroalcoholic extract of Murraya koenigii and Coriandrum sativum leaves and compared it with standard drug in an animal model.Methods: Hydroalcoholic extracts of M. koenigii and C. sativum leaves were obtained using Soxhlet apparatus. The central analgesic property was screened by hot plate method in mice and tail flick method in rats. The pain reaction time (PRT) was measured at 30, 60, and 120 min. The peripheral analgesic activity was evaluated by acetic acid induced writhing in mice.Results: In hot plate method M. koenigii leaves extract at both doses and tramadol showed significant increase in PRT at 30, 60, and 120 min compared with control group. C. sativum leaves extract showed significant increase in PRT only at 60 and 120 min compared to control group. In tail flick method M. koenigii leaves extract at both doses, higher dose of C. sativum leaves extract and tramadol showed significant increase in PRT at 30, 60, and 120 min compared with control group. Higher dose of M. koenigii leaves extract (200 mg/kg) was comparable with standard drug tramadol in both the methods. M. koenigii leaves extract at both dose showed significant reduction in the number of writhing but C. sativum leaves extract failed to show any significant reduction in the number of writhing compared with control. Higher dose of M. koenigii leaves extract was comparable with standard drug tramadol.Conclusion: M. koenigii leaves extract showed both peripheral and central analgesic effect while C. sativum leaves extract showed only peripheral analgesic effect.


2019 ◽  
Vol 10 (4) ◽  
pp. 313-322
Author(s):  
Farshid Etaee ◽  
◽  
Arezoo Rezvani-Kamran ◽  
Mohammad Taheri ◽  
Ghazaleh Omidi ◽  
...  

Introduction: Methamphetamine (Meth) and Buprenorphine (BUP) modulate pain perception. However, the antinociceptive effects of their interactions, which affect through different systems, are unclear in rats. This study aimed to compare the analgesic effects of Meth, BUP, and their coadministration, as well as the effect of withdrawal from these substances on nociception in male rats. Methods: In this experiment, 40 male Wistar rats (weight: 250-300 g) were categorized into four groups: control, Meth, BUP, or BUP+Meth. After seven days of treatments, the antinociceptive effects were assessed using the hot plate and the tail flick tests. The differences among the groups were analyzed with ANOVA and Tukey’s post hoc tests. P values less than 0.05 were considered significant. Results: Meth and BUP increased the reaction times during the hot plate and tail flick tests. The combination of Meth and BUP increased reaction time more than Meth or BUP alone.  Conclusion: The significantly high reaction times in rats treated with Meth and BUP indicate that these substances have antinociceptive effects. In addition, Meth enhanced the antinociceptive effects of BUP. These synergistic effects might occur through the dopaminergic, serotonergic, and or adrenergic systems.


1985 ◽  
Vol 86 (5) ◽  
pp. 671-689 ◽  
Author(s):  
M E Pierce ◽  
J C Besharse

In lower vertebrates, cone retinomotor movements occur in response to changes in lighting conditions and to an endogenous circadian clock. In the light, cone myoids contract, while in the dark, they elongate. In order to test the hypothesis that melatonin and dopamine may be involved in the regulation of cone movement, we have used an in vitro eyecup preparation from Xenopus laevis that sustains light- and dark-adaptive cone retinomotor movement. Melatonin mimics darkness by causing cone elongation. Dark- and melatonin-induced cone elongation are blocked by dopamine. Dopamine also stimulates cone contraction in dark-adapted eyecups. The effect of dopamine appears to be mediated specifically by a dopamine receptor, possibly of the D2 type. The dopamine agonist apomorphine and the putative D2 agonist LY171555 induced cone contraction. In contrast, the putative D1 agonist SKF38393-A and specific alpha 1-, alpha 2-, and beta-adrenergic receptor agonists were without effect. Furthermore, the dopamine antagonist spiroperidol not only blocked light-induced cone contraction, but also stimulated cone elongation in the light. These results suggest that dopamine is part of the light signal for cone contraction, and that its suppression is part of the dark signal for cone elongation. Melatonin may affect cone movement indirectly through its influence on the dopaminergic system.


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