Showing 4 results for Khakpay
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.
Roghaieh Khakpay, Sanam Ansari, Fatemeh Khakpay,
Volume 20, Issue 8 (11-2017)
Abstract
Abstract
Background: Paragigantocellularis lateralis (LPGi) nucleus plays a key role in the processing of pain information related to the descending pain modulation. Also, 17β-estradiol is involved in the pain modulation. The aim of the present study was to investigate the role of estrogen receptors of LPGi nucleus in the 17β-estradiol-induced pain modulation in the ovariectomized rats.
Materials and Methods: In this study, the female Wistar rats (180-250 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 LPGi nucleus was performed. First, drugs were injected and 15 minutes later 50 μl of 5% formalin was injected into the rat's hind paw; and then, formalin-induced paw jerking behavior was recorded for 60 min.
Results: Our results indicated that intra-LPGi injection of 17β-estradiol significantly attenuated paw jerking behavior in the both phases of formalin test. Intra-LPGi injection of estrogen receptor antagonist (ICI 182,780), had no effect on the paw jerking behavior. Pre-treatment of LPGi nucleus by ICI 182,780 counteracted the anti-nociceptive effect of 17β-estradiol both in the acute and in the chronic phases of formalin-induced paw jerking behaviour.
Conclusion: Based on the results of this study, it can be concluded that the intra-LPGi 17β-estradiol produces modest analgesia on the formalin-induced inflammatory pain in the ovariectomized rats, which is probably mediated via the esterogen receptors of this nucleus.
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.
Zahra Nanava, Homeira Hatami Nemati, Hatam Ahmai, Roghaieh Khakpay,
Volume 29, Issue 1 (3-2026)
Abstract
Introduction: Methamphetamine is a powerful psychostimulant that has been significantly abused in recent years. Buprenorphine, a derivative of morphine alkaloids, is effective in treating opioid addiction.
Methods: This experimental study involved eight groups of seven male rats each. It examined the effects of a 5-day intraperitoneal injection of methamphetamine, buprenorphine, their interactions, and methamphetamine withdrawal on the expression of histamine and histamine N-methyltransferase genes in the lumbar spinal cord. The data were analyzed using One-way ANOVA.
Results: The intraperitoneal administration of 10 mg/kg of methamphetamine and 6 or 10 mg/kg of buprenorphine over five days did not change the expression levels of the histamine or histamine N-methyltransferase genes in the lumbar spinal cord of male rats. However, discontinuing methamphetamine led to an increase in the expression of both genes in this area (P < 0.01). Furthermore, when examining the interaction between the two drugs, it was found that the expression of the histamine N-methyltransferase gene was significantly higher in the group receiving methamphetamine plus 10 mg/kg buprenorphine compared to the methamphetamine-only group (P < 0.01).
Conclusions: Based on the results of this study and the mechanisms proposed in previous studies, it seems that methamphetamine withdrawal and/or the use of buprenorphine as a possible therapeutic approach can lead to the stabilization of the physiological balance of the central nervous system by temporarily increasing brain histamine, and thus help reduce the complications of methamphetamine abuse.
