Anticonvulsant effect of minocycline on pentylenetetrazole-induced seizure in mice: involvement of nitric oxide and N-methyl-d-aspartate receptor

2018 ◽  
Vol 96 (8) ◽  
pp. 742-750 ◽  
Author(s):  
Hossein Amini-Khoei ◽  
Nastaran Kordjazy ◽  
Arvin Haj-Mirzaian ◽  
Shayan Amiri ◽  
Arya Haj-Mirzaian ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nmda Receptor ◽  
Seizure Threshold ◽  
Anticonvulsant Effect ◽  
Acute Administration ◽  
Nmda Receptor Antagonists ◽  
Receptor Antagonists ◽  
Nitrite Level ◽  
Nos Inhibitor ◽  
Neuronal Nos

Anticonvulsant effects of minocycline have been explored recently. This study was designed to examine the anticonvulsant effect of acute administration of minocycline on pentylenetetrazole-induced seizures in mouse considering the possible role of the nitric oxide/N-methyl-d-aspartate (NMDA) pathway. We induced seizure using intravenous administration of pentylenetetrazole. Our results showed that acute administration of minocycline increased the seizure threshold. Furthermore, co-administration of subeffective doses of the nonselective nitric oxide synthase (NOS) inhibitor NG-l-arginine methyl ester (10 mg/kg) and the neuronal NOS inhibitor 7-nitroindazole (40 mg/kg) enhanced the anticonvulsant effect of subeffective doses of minocycline (40 mg/kg). We found that inducible NOS inhibitor aminoguanidine (100 mg/kg) had no effect on the antiseizure effect of minocycline. Moreover, l-arginine (60 mg/kg), as a NOS substrate, reduced the anticonvulsant effect of minocycline. We also demonstrated that pretreatment with the NMDA receptor antagonists ketamine (0.5 mg/kg) and MK-801 (0.05 mg/kg) increased the anticonvulsant effect of subeffective doses of minocycline. Results showed that minocycline significantly decreased the hippocampal nitrite level. Furthermore, co-administration of a neuronal NOS inhibitor like NMDA receptor antagonists augmented the effect of minocycline on the hippocampal nitrite level. In conclusion, we revealed that anticonvulsant effect of minocycline might be, at least in part, due to a decline in constitutive hippocampal nitric oxide activity as well as inhibition of NMDA receptors.

Possible Involvement of Endogenous Opioids and Nitric Oxide in the Anticonvulsant Effect of Acute Chloroquine Treatment in Mice

2017 ◽  
Vol 41 (S1) ◽  
pp. S630-S630
Author(s):  
A. Abkhoo
Keyword(s):  
Nitric Oxide ◽  
Effective Dose ◽  
Clonic Seizure ◽  
Endogenous Opioids ◽  
Seizure Threshold ◽  
Anticonvulsant Effect ◽  
Nitric Oxide Signaling ◽  
Nos Inhibitor ◽  
Neuronal Nos ◽  
Anticonvulsant Effects

IntroductionChloroquine, a 4-aminoquinoline derivative, has long been used for the treatment of malaria and rheumatological disorders, including rheumatoid arthritis and systemic lupus erythematosus. Accumulating evidence now suggests potential use of chloroquine as a neuroprotectant. Studies have shown that nitric oxide (NO) pathway is involved in the chloroquine actions. Considering the fact that nitrergic neurotransmission plays a crucial role in the central nervous system functioning, in the present study we evaluated whether nitrergic system is involved in the anticonvulsant effects of chloroquine in a model of clonicseizure in mice.MethodsClonic seizure threshold was determined by infusion of pentylenetetrazole (PTZ, 0.5%) at a constant rate of 1 mL/min into the tail vein of male Swiss mice (23–29 g). Minimal dose of PTZ (mg/kg of mice weight) needed to induce clonicseizure was considered as an index of seizure threshold.ResultsChloroquine (5 mg/kg, acutely 30 min before test, intraperitoneally), i.p significantly increased the seizure threshold. Acute co-administration of a non-effective dose of the non-selective NO synthase (NOS) inhibitor, L-NAME (L-NG-Nitro-L-arginine methyl ester hydrochloride,5 mg/kg, i.p.) or the selective inhibitor of neuronal NOS, 7-NI (7-nitroindazole, 40 mg/kg, i.p.) with an effective dose of chloroquine (5 mg/kg) inhibited its anticonvulsant effects. Co-administration of a non-effective dose the selective inducible NOS inhibitor, aminoguanidine (100 mg/kg, i.p.) with chloroquine 5 mg/kg did not alter its anticonvulsant effects.ConclusionChloroquine increases the PTZ-induced clonic seizure threshold in mice. We demonstrated for the first time that nitric oxide signaling probably through neuronal NOS could be involved in the anticonvulsant effects of chloroquine in this model of seizure in mice.Disclosure of interestThe author has not supplied his/her declaration of competing interest.

Involvement of Glutamate Receptors in Strychnine- and Bicuculline-induced Allodynia in Conscious Mice

1996 ◽  
Vol 84 (5) ◽  
pp. 1215-1222 ◽  
Author(s):  
Masahiko Onaka ◽  
Toshiaki Minami ◽  
Isao Nishihara ◽  
Seiji Ito
Keyword(s):  
Nitric Oxide ◽  
Methylene Blue ◽  
Nmda Receptor ◽  
Glutamate Receptor ◽  
Intrathecal Injection ◽  
Intrathecal Administration ◽  
Nmda Receptor Antagonists ◽  
Receptor Antagonists ◽  
Stainless Steel Needle ◽  
Inhibitory Neurotransmitters

Background Glycine and gamma-aminobutyric acid (GABA) are inhibitory neurotransmitters that appear to be important in sensory processing in the spinal dorsal horn. Intrathecal administration of strychnine (strychnine-sensitive glycine receptor antagonist) or bicuculline (GABAA antagonist) was reported to induce allodynia. Although the strychnine-induced allodynia was shown to be mediated through the N-methyl-D-aspartate (NMDA)-type glutamate receptor, it is not clear whether the bicuculline-evoked-allodynia is mediated through the glutamate receptor system or how different the allodynia induced by strychnine and bicuculline are. Methods Male ddY mice weighing 20 +/- 2 g were used in this study. A 27-G stainless-steel needle attached to a microsyringe was inserted between the L5 and L6 vertebrae by a slight modification of the method of Hylden and Wilcox. Drugs in vehicle were injected slowly into the subarachnoid space to conscious mice at 22 +/- 2 degrees C. The volume of the intrathecal injection was 5 microliters. Studies on allodynia were carried out essentially according to the method of Yaksh and Harty. Results The intrathecal administration of strychnine or bicuculline in conscious mice resulted in allodynia elicited by nonnoxious brushing of the flanks. The maximum allodynia induced by strychnine was observed 5 min after intrathecal injection, but that induced by bicuculline was observed 10 min after intrathecal injection. Both responses gradually decreased over the experimental period of 50 min. The allodynia induced by strychnine was dose-dependently relieved by NMDA receptor antagonists (D-AP5, ketamine, and 7-C1-KYNA) and non-NMDA receptor antagonists (GAMS and CNQX) but not by metabotropic receptor antagonists (L-AP3 and L-AP4). On the other hand, allodynia induced by bicuculline was dose-dependently relieved by GAMS, L-AP3, and L-AP4, but not by D-AP5, ketamine, 7-C1-KYNA, and CNQX. Whereas the strychnine-evoked allodynia was dose-dependently relieved by the nitric oxide synthase inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME) and the soluble guanylate cyclase inhibitor methylene blue, the bicuculline-induced one was dose-dependently relieved by methylene blue but not by L-NAME. Conclusions These results demonstrate that both strychnine- and bicuculline-evoked allodynia were mediated through pathways that include the glutamate receptor and nitric oxide systems but in a different manner. the current study suggests that GABA and glycine may modulate responses to an innocuous tactile stimulus as inhibitory neurotransmitters at presynaptic and postsynaptic sites in the spinal cord, respectively.

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