Showing 6 results for Formalin Test
Vahid Sheibani, Mohammad Ali Afarinesh Khaki, Zahra Hajizadeh, Mandana Jafari, Razeieh Arabnezhad, Ali Shamsizadeh,
Volume 11, Issue 3 (9-2008)
Abstract
Background: Pain is an unpleasant feeling which humans experience. It is a warning sign of the damaged tissue. Due to the awful sense of pain, scientists always attempt to relieve it. Retinoic acid (RT), an active metabolite of natural vitamin A has important roles in modulation of the inflammatory responses. The aim of the present study was to analyze the pain threshold of rats which had microinjections of RT, applying acute and chronic models. Methods and Materials: In this study, the tail flick and formalin tests were used to determine pain threshold. In each test, the acute and chronic pain thresholds of 252 Wistar male rats (275 ± 25 gr) were assayed. The druge were injected in the acute model one-dose30 minutes before behavioral testing and in chronic model two-dose for one or two-weeks. The rats of both models divided randomly into six groups (n=7). In four treatment groups retinoic acid (RT) intra cerebro ventricular (i.C.V) were injected as dosagc of 0.5, 3 and 6 (µg/kg) micrograms per kilogram. In control group, was microinjected by ACSF. In vehicle group injected RT solvent (DMSO+ Distil water). Results: The resuits Showed acute injection of RT did not change pain thresholds in the tail-flick methd, but the chronic administration of RT (0.5, 1, 3, 6 µg/kg) reduced tail-flick latencies of the rats (p<0.05) in compare to DMSO group. The threshold of pain in the first phase of formalin test was reduced after injection of 3µg/kg of RT for two weeks. Conclusion: It was concluded that chronic i.c.v. injections of RT can induce significant hyperalgesia in rat.
Akram Eidi , Sara Moghadam-Kia , Jalal Zarringhalam Moghadam, Shamsali Rezazadeh, Maryam Eidi,
Volume 14, Issue 4 (9-2011)
Abstract
Background: In traditional medicine, Olive oil (Olea europaea L.) from Oleaceae family is known as a remedy for alleviating pain. This study investigates the antinociceptive effects of olive oil on male adult NMRI mice.
Materials and Methods: In this experimental study, using the acetic acid-induced writhing and formalin tests, the anticipative effects of olive oil were evaluated. Olive oil (1, 5, and 10 ml/kg bodyweight), morphine (10 mg/kg bodyweight), and indomethacin (10 mg/kg bodyweight), as standard drugs, were injected intraperitoneally. The control group did not receive any treatment. Data were analyzed using one-way ANOVA and Tukey test.
Results: Olive oil significantly decreased acetic acid-induced abdominal writhes (P<0.001). Olive oil could only decrease the induced pain in the second phase of the formalin test (P<0.001).
Conclusion: Olive oil decreases inflammatory pain (the second phase of the formalin test and acetic acid-induced writhing tests), but it has no significant effects on neurogenic pain (the first phase of the formalin test). Further studies are required to elucidate the antinociceptive effects of olive oil.
Zahra Hadi Chegeni, Shahrbanoo Oryan, Abbas Zare Mirak Abadi, Azam Bakhtiarian, Somayyeh Akbari, Giti Ghamami, Khadijeh Nazari,
Volume 18, Issue 3 (6-2015)
Abstract
Background: There have been numerous reports of snake venoms being employed as analgesics in attempts to relieve severe pain associated with cancer, immune dysfunction and viral infections. This study investigates the antinociceptive effects of iranian cobra snake venom (Naja naja oxiana) in comparison with morphine and lidocain on laboratorial femal mice.
Materials and Methods: This study has been done on 48 NMRI female mice of 18-20 g in weight. Antinociceptive activeity of snake venom was evaluated by formalin test. In this test, the animals were divided into 6 groups (each group consisting of 8 mice): Sham, positive Control (receiving morphine at dose of 5 mg/kg, and receiving lidocain at dose of 20 mg/kg), and experimental groups receiving venom at doses of 1, 3 and 4.5 µg/mice. In all groups, the formalin test was recorded for 60 min after administration of venom and drugs in mice. Data were analyzed using one-way ANOVA and Tukey test.
Results: The results showed that the venom of Naja naja oxiana decreased nociception meaningfully in both acute and chronic phases. We also showed that this venom revealed even a better analgesic activity in comparison with morphine and lidocain.
Conclusion: This study showed that the antinociceptive effect of the venom was mediated through central nervous system and peripheral mechanisms. Although details of the mechanism remain unclear, and further studies should be considered to demonstrate its therapeutic effects.
Olya Moshiri, Javad Sajedianfard, Mina Gheisari,
Volume 20, Issue 5 (8-2017)
Abstract
Abstract
Background: Pain is a protective process in the body. There are different pathways for pain control in the central nervous system. Descending pain control system is one of pathways. The periaqueductal gray (PAG) is a structure known for its role in pain transmission and modulation. The aim of this study is to investigate the percent of interaction between the left and right PAG in unilateral left foot induced pain.
Materials and Methods: In this study, 60 rats (280+30g) in six groups were used (3test groups and 3 controls groups). In test groups, 0.5 microliter lidocaine was injected in the left PAG, right PAG or both to make local anesthesia. In control groups, 0.5 microliter of normal saline were injected. After 15 minutes, 50 microliter of 2.5% of formalin were injected subcutaneously to right hind paw of rats and nociception was detected in every 15 seconds for one hour.
Results: The induction of unilateral pain (left hind paw) in rats, can affect not only the ipsilateral but also the contralateral PAG nucleus.
Conclusion: This study showed that the left and right PAG nuclei have significant role on unidirectional nociception in formalin test in rats. The contralateral PAG, however, has a minor effect on nociception.
Roghaieh Khakpay, Hanieh Feyzi, Farzam Sheikhzadeh Hesari,
Volume 20, Issue 7 (10-2017)
Abstract
Abstract
Background: 17β-Estradiol modulates nociception by binding to the estrogen receptors and also by allosteric interaction with other membrane-bound receptors like the NMDA receptors. The paragigantocellularis lateralis nucleus (LPGi) is also involved in the pain modulation. In this study, the role of NMDA receptors of the LPGi nucleus has been investigated in the 17β-estradiol-induced pain modulation in the ovariectomized rats.
Materials and Methods: In this study, the female Wistar rats in the range of 200-270 gr were used. In order to study the role of the NMDA receptors in the 17β-estradiol-induced pain modulation in the ovariectomized rats, primarily, rats were bilaterally ovariectomized and immediately cannulation of the LPGi nucleus was performed. Then, drugs were injected and 15 minutes later 50 μl of 5% formalin was injected into the rat's hind paw; and formalin-induced paw jerking behaviour was recorded for 60 min.
Results: The results of the present study showed that the intra-LPGi injection of 17β-estradiol significantly reduced the paw jerking behavior both in the first and in the second phases of formalin test. Pretreatment of the LPGi nucleus by NMDA receptor antagonist (AP5) neutralized the antinociceptive effect of 17β-estradiol on the paw jerking frequency in the both phases of formalin test; and induced hyperalgesia in the both phases of this behavior.
Conclusion: These results indicated that the intra-LPGi injection of 17β-estradiol produces modest analgesia on the formalin-induced inflammatory pain. Therefore, it can be concluded that the NMDA receptors of the paragigantocellularis lateralis nucleus are probably involved in the antinociceptive effect of 17β-estradiol in the ovariectomized rats.
Zahra Heidarzadeh, Roghaieh Khakpay, Seyed Mahdi Banan Khojasteh, Fatemeh Khakpai,
Volume 22, Issue 2 (6-2019)
Abstract
Background and Aim: Intra-paragigantocellularis lateralis (LPGi) injection of 17β-estradiol produces robust antinociceptive effect on the inflammatory pain in the both male and ovariectomized female rats which is possibly mediated through estrogen receptors of this nucleus. This study aimed to examine the role of estrogen receptors in the pain modulatory effect of 17β-estradiol during proestrus phase of female rats.
Materials and Methods: In this study, the female Wistar rats in the range of 200-270 gr were used. For studying the influence of intra-LPGi injection of 17β-estradiol on the acute inflammatory pain modulation, cannulation into the LPGi nucleus was performed after entrance into the proestrus cycle. After entrance in the proestrus phase once again, drugs were injected and 15 minutes later, formalin was injected into the rat's hind paw. Then, formalin-induced paw jerking behavior was recorded for 60 min.
Ethical Considerations: This study with research ethics code IR.TBZMED.VCR.REC.1397.385 has been approved by research ethics committee at Tabriz University of Medical Sciences.
Findngs: The results of this study showed that intra-LPGi injection of 17β-estradiol during proestrus phase significantly attenuated paw jerking frequency both in the first (p<0.01) and in the second (p<0.001) phases of formalin test. Pretreatment of the LPGi nucleus with estrogen receptor antagonist (ICI182,780) neutralized the 17β-estradiol-induced analgesia.
Conclusion: Our results indicated that intra-LPGi injection of 17β-estradiol induces robust analgesia on the inflammatory pain during the proestrus phase. Thus, it can be concluded that the antinociceptive effect of 17β-estradiol is probably mediated via estrogen receptors.
