Montelukast reduces seizures in pentylenetetrazol-kindled mice

Cysteinyl leukotrienes (CysLTs) have been implicated in seizures and kindling; however, the effect of CysLT receptor antagonists on seizure frequency in kindled animals and changes in CysLT receptor expression after pentylenetetrazol (PTZ)-induced kindling have not been investigated. In this study, we evaluated whether the CysLT1 inverse agonist montelukast, and a classical anticonvulsant, phenobarbital, were able to reduce seizures in PTZ-kindled mice and alter CysLT receptor expression. Montelukast (10 mg/kg, sc) and phenobarbital (20 mg/kg, sc) increased the latency to generalized seizures in kindled mice. Montelukast increased CysLT1 immunoreactivity only in non-kindled, PTZ-challenged mice. Interestingly, PTZ challenge decreased CysLT2 immunoreactivity only in kindled mice. CysLT1 antagonists appear to emerge as a promising adjunctive treatment for refractory seizures. Nevertheless, additional studies are necessary to evaluate the clinical implications of this research.

Effects of Vitex agnus - castus extract on after- discharge threshold, seizure stages and kindling acquisition in male rats

Vitex agnus - castus extract [Vitex] is available in dosage forms for female disorders treatment. This extract has shown controversial effects against seizures induced by Maximal electroshock [MES] or pentylenetetrazole [PTZ]. In the present study the anti-seizure activity of Vitex against acquisition of amygdala kindling was evaluated in male rats. Methods: Intact male rats were stereotaxically implanted with a tripolar and 2 monopolar electrodes in amygdala and dura respectively. The threshold of AD emerging was determined in each animal. Then, Vitex or solvent was injected and AD threshold was determined again. Also, Vitex injection was continued daily and seizure stages [S1 to S5] and ADDs were recorded 30 min post Vitex injection till development of full kindling. Vitex treatment increased the AD threshold significantly more than 2.5 times and decreased the after-discharge duration [ADD]. Although, the number of trials increased significantly by Vitex for exhibition of stages 1 [S1] to S3, but this effect was not significant for development of S4 and S5 [generalized seizures]. The cumulative ADDs difference between control and Vitex group was only significant for S3 - S5. Conclusions: Vitex may induce a protective effect via increment of stimulation threshold and decrement of ADD at least against focal epilepsy in amygdala neurons. Regarding to its limited effects on kindling acquisition at late stage with generalized seizures, Vitex may postpone the progress of epileptic activity at initial stages

[Effect of aspirin on learning and memory impaired by pentylenetetrazole kindling in male rat]

In recent years many studies have reported that aspirin could have beneficial effect on learning and memory in different diseases of central nervous system. The objective of present study was to explore the effect of aspirin on learning and memory of Rats in pentylenetetrazole kindling model. In this experimental study Rats were divided randomly into six groups [n=8]. Animals in three groups received aspirin [15 and 30 mg/kg, orally] and saline, one week before and during induction of kindling, respectivley. Kindling was induced in these groups by administration of pentylenetetrazole [PTZ: 40 mg/kg, ip]. Two groups of animals received only aspirin 25 and 30 microg/kg orally. Other group received only saline throughout the study and served as health control group. After induction of kindling the learning and memory of Rats was tested in shuttle box. Study was divided to three stages of adaptation, acquisition and retention test. Initial Latency [IL] time before electrical shock and Step through latency [STL] time, 20 min or 24h after acquisition was evaluated as learning and memory index. Locomotor activity was also evaluated in open filed test. PTZ kindling significantly decreased Initial Latency and Step through latency time, 20 min or also 24h after acquisition, and aspirin significantly increased these times in kindled animals [p<0.05]. Aspirin also had no significant effect on locomotor activity of animals. This study showed that the administration of aspirin to kindled Rats improved learning and memory impairments induced by pentylenetetrazole kindling

[Comparison the effects of dietary administration of isomeric fatty acids on chemical kindling in second generation of wistar kindled rats]

Impressive researches demonstrate the importance of essential fatty acids for many physiological and behavioral mechanisms in both humans and animals. Essential fatty acids must be supplied via the diet. In this study we assessed the dietary effects of cis and trans fatty acids on seizures induced by Pentylenetetrazol [PTZ] in rats. In this experimental study animals were divided into four groups. In the three case groups; cis, trans or cis + trans fatty acids were added to the standard food of rats and in control group only standard food was dietary administrated. After one month, kindling was established in rats with PTZ in subconvulsive dose [45mg/kg i.p.]. Convulsing activities were monitored for 20 mm. Five stages of convulsing activities were observed. If after three consecutive sessions the animal was in the fifth stage, it was considered as a kindled animal. Data was analyzed using K-S, T, Tukey tests and analysis of variance. Results showed that the convulsion stage in trans group was significantly more than others. Also it was found that duration of the fifth stage in trans group was significantly more than control and cis groups. Results suggest that, administering sis and trans fatty acids have some effects on PTZ induced kindling in second generation of the rats who were kindled before. More severe seizure and longer duration of seizure was seen in trans group comparing to cis group

[Effect of progesterone administration in newborns rats on pentylenetetrazol kindling susceptibility after maturity]

Regarding the high prevalence of epileptic seizures, its complications and the necessity to control them, this study was carried out in order to assess the role of progesterone administration in newborn rats on Pentylenetetrazol [PTZ] kindling susceptibility after maturity. This experimental study was carried out on 32 newborn Wistar rats. Rats were randomly divided into four groups, which are as follows: progesterone-injected females, progesterone-injected males, sesamoid-injected females and sesamoid-injected males. Progesterone and sesamoid groups were injected with progesterone [100 mg/Kg] and sesamoid [100 mg/Kg] respectively. Sixty days after injection chemical kindling in the rats was analyzed by PTZ administration. Progesterone significantly increased the susceptibility for PTZ kindling in female rats however; it did not have a significant effect on seizure parameters in male rats. The results of this study suggest that chronic administration of progesterone can only increase susceptibility for chemical kindling in female rats and not in the males

role of adenosine A1 receptor activity of piriform cortex neurons on amygdala kindled seizures in rats

Considering the anticonvulsant effects of A1 Adenosine Receptors and the anatomical connections between piriform Cortex and Amygdala, in this study, the role of A1 adenosine receptors activity of piriform cortex neurons on amygdala kindled seizures was investigated in rats. The rats were fully kindled by daily electrical stimulation of amygdala. N6-cyclohexyleadenosine [CHA; 1,10 and 100 mM], as a selective A1 agonist and 1,3-dimethyl-8-cyclohexylexantine [CPT; 20 and 10 mM], as a selective A1 antagonist were microinjected [0.5ml, 0.25 ml/min] into the piriform cortex. Animals were stimulated at 5, 15 or 90 min after drug microinjection and seizure parameters were measured. Intra-piriform CHA [10 or 100 mM] reduced afterdischarge duration and stage 5 seizure duration and prolonged stage 4 latency significantly. Pretreatment with CPT [10 mM] 5 min before CHA [100 mM] eliminated the effects of CHA. These observations suggest that A1 adenosine receptors activity in piriform cortex reduced the seizure severity and attenuated the distribution of seizure activity to other brain regions

Antiepileptic activity of Panax ginseng against pentylenetetrazole induced kindling in rats.

In the present study, Panax ginseng was evaluated for its antiepileptic activity against pentylenetetrazole (PTZ) induced chemical kindling in rats. PTZ was injected at the dose of 30 mg/kg, i.p. on alternate days and the occurrence of generalized tonic clonic convulsions were considered as the end point. One group received Panax ginseng every day, at a dose of 100 mg/kg, 30 min prior to PTZ injection whereas the other group received an equal volume of distilled water to serve as control. In a separate group the rats were evaluated for motor performance tests after Panax ginseng. The rats treated with Panax ginseng showed significant protection as compared to vehicle treated PTZ injected rats. The study suggests to potential of Panax ginseng against seizures.

Levobupivacaína: ¿Una nueva opción? / Levobupivacaine: A new option?

La investigación de nuevos anestésicos locales con un aumento de la liposolubilidad de sus moléculas ha permitido hallar drogas con mayor potencia y duración del efecto. Sin embargo, los mismos cambios moleculares que incrementan la duración de acción y la potencia también pueden aumentar la toxicidad local y sistémica. En el caso de una excesiva dosis utilizada, ya sea por una rápida absorción o por una inyección intravascular inadvertida, durante el procedimiento para el bloqueo se pueden producir efectos sistémicos de importancia. El primer sistema afectado es el nervioso central, donde produce una excitación, llegando luego a deprimir el sistema cardiovascular. Los estudios comparativos para numerosas indicaciones no han podido demostrar fehacientemente diferencias en cuanto a la toxicidad de la levobupivacaína, la ropivacaína y la bupivacaína.

Actividad de la Indigofera suffruticosa Mill en la epilepsia crónica experimental y su relación con aminoácidos neurotransmisores / Activity of Indigofera suffruticosa Mill in experimental chronic epilepsy and its relation to neurotransmitter amino acids

Se determinaron los niveles de aminoácidos plasmáticos en el modelo de epilepsia experimental kindling inducido por lidocaína. Se ensayaron 5 grupos: un grupo de animales sin tratamiento, otro de animales kindleados, otro de animales kindleados al que se le suministró el menstruo y los 2 últimos grupos a los cuales se les adminitró por vía oral la dosis de 0.06 g/kg pc del extracto fluido de la planta Indigofera suffructicosa (añil cimarrón), en un grupo durante el tratamiento y en otro antes y durante el tratamiento en el desarrollo del modelo. Los niveles de aminoácidos, taurina, glicina, tirosina, fenilalanina, ácido glutámico y triptófano fueron cuantificados en un analizador de aminoácidos, y se encontró diferencias significativas (p < 0.05) en al ácido glutámico, taurina y glicina en los animales tratados con respecto a los controles. Se realizaron mediciones conductuales a lo largo de la experiencia

Plantago major L. (Llanten) y epilepsia I. Efecto de las decocciones de hojas y raices sobre el foco penicilinico en ratas curarizadas / Plantago major L. and epilepsy I. Effects of decoction of leaves and roots on penicillinic focus in rats receiving curare

Se realizo una evaluacion preliminar del efecto de los extractos acuosos de hojas verdes y raices secas de Plantago major L. sobre las espigas inducidas por aplicacion topica de penicilina en el electrocoticograma de la rata. Los experimentos se llevaron a acabo en ratas machos, de la cepa Wistar con un peso corporal de 150-250 gramos. La administracion intraperitoneal de la decoccion de la raiz seca al 6 porciento produjo un incremento de la amplitud de las espigas inducidas en la corteza occipital de las ratas. Este resultado revela un aumento de la excitacion neuronal y alerta contra posibles efectos colaterales indeseables en el uso terapeutico de esta planta

Pentylenetetrazol-induced kindling in animals: protective effect of BR-16A.

Repeated administration of pentylenetetrazol (PTZ, 30 mg/kg, thrice a week) to mice for 9 weeks and subsequent challenge of the animals with the same dose of PTZ on the last chronic dose produced chemical kindling. The mice showed myoclonic jerks, clonus, Straub's tail, falling back response and full blown convulsions. The anticonvulsant profile of chronic administration of BR-16A (100 and 500 mg/kg) was studied in this model of epilepsy. BR-16A offered protection against PTZ-induced chemical kindling. The per cent animals showing myoclonic jerks and clonus was reduced to 40 and 34 with 100 mg/kg and 54 and 27 with 500 mg/kg of BR-16A, respectively. The protective effect was compared with diazepam (1 mg/kg, ip). The results demonstrated GABAA receptor mediated PTZ-induced kindling and protective effect of BR-16A therein.

Dihydropyridine group of calcium channel antagonist in epilepsy.

Effects of intraperitoneally administered dihydropyridine calcium channel blocker-nifedipine (NIF) 5 mg/kg and diphenylhydantoin (DPH) 5 mg/kg were studied on hippocampal kindling and maximum electro shock thresholds (MEST). All the NIF injected rats showed complete suppression of behavioral seizure after the 3rd injection. Few of the DPH rats had increased epileptic activity for two days and others--absence of Grade--5 seizure after the 5th DPH injection. However, all showed partial seizure suppression subsequently. Neither NIF nor DPH could suppress the after discharge (AD). MEST were not affected by NIF although DPH showed a complete suppression of posterior limb extensor tone in all the rats.

Bilateral microinjection of ethosuximide into the substantia nigra does not prevent amygdala-kindled seizures

Male Wistar rats were sugjected to daily sessions of electrical amygdala kindling until a generalized seixure was observed on five consecutive days. Bilateral microinections (0.5 micronl) of ethosuximide (ETX) (10 pg/micronl) or saline were then administered though guide cannulas into the substantia nigra (pars reticulata). No significant difference was observed between the ETX (N = 8) and saline (N = 8) groups in duration of afterdischarge or in the latency for stage 5 generalized seizures. Our results indicate that ETX applied to the substantia nigra is not effective in suppressing amydala-kindled seizure