Modifying effect of estradiol and progesterone on epileptic activity of the rat brain

Gevorkyan, E. S.; Nazaryan, Karen; Kostanyan, Amalia

doi:10.1007/bf01197874

Cited by 13 publications

(4 citation statements)

References 6 publications

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“…Latencies to the first minimal clonic seizure (MCS) as well the first generalized tonic-clonic seizures (GTCS) were also higher in OVX rats than sham operated ones when a high dose of PTZ was administered [9]. All of this findings support the proconvulsant effects of estrogen which has been repeatedly reported [7, 55, 56]. In contrast, it was shown that estrogen treatment may decrease the pilocarpine-induced temporal lobe epilepsy in animal model [57].…”

Section: Discussionsupporting

confidence: 52%

Tamoxifen Mimics the Effects of Endogenous Ovarian Hormones on Repeated Seizures Induced by Pentylenetetrazole in Rats

et al. 2013

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In the present study, the effects of tamoxifen on pentylenetetrazole (PTZ)-induced repeated seizures and hippocampal neuronal damage in ovariectomized rats were investigated. Thirty seven virgin female Wistar rats were divided to: (1) control, (2) sham-PTZ, (3) sham-PTZ-tamoxifen (sham-PTZ-T), (4) Ovariectomized -PTZ (OVX-PTZ) and (5) OVX-PTZ-tamoxifen (OVX-PTZ-T) groups. The animals of groups 3 and 5 were injected by tamoxifen (10 mg/kg) on 7 consecutive days. After 7 days of tamoxifen injection, they also were then injected by tamoxifen 30 min prior each PTZ injection. PTZ (40 mg/kg) was injected on 6 consecutive days and the animal behaviors were observed for 60 min. The histological methods were then used to determine dark neurons in hippocampus. A significant decrease in the seizure score was seen in OVX-PTZ group compared to Sham-PTZ. The animals of OVX-PTZ-T group had a significant higher seizure score compared to OVX-PTZ group. The dark neurons in DG of OVX group were lower than sham group (p<0.01). The numbers of dark neurons in CA1 area of OVX-PTZ-T group was higher than OVX-PTZ group (p<0.05) compared to control, the numbers of dark neurons in CA3 area showed a significant increase in Sham-PTZ and OVX-PTZ group (p<0.05 and p<0.01 respectively). Dark neurons in OVX-PTZ-T group were higher than OVX-PTZ group (p<0.05). It is concluded that pretreatment of the ovariectomized rats by tamoxifen increased PTZ-induced seizure score and dark neurons. It might be suggested that tamoxifen has agonistic effects for estrogen receptors to change the seizure severity.

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Section: Discussionsupporting

confidence: 52%

Tamoxifen Mimics the Effects of Endogenous Ovarian Hormones on Repeated Seizures Induced by Pentylenetetrazole in Rats

et al. 2013

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“…In our another study, the latencies to the first minimal clonic seizure (MCS) as well as the first generalized tonic-clonic seizures (GTCS) were also higher in OVX rats than sham operated ones when a high dose of PTZ was administered [14]. All of this findings support the pro-convulsant effects of estrogen which has been repeatedly reported [12,55,56]. In contrast, it has been reported that estrogen treatment may decrease the pilocarpine-induced temporal lobe epilepsy in animal model [57].…”

Section: Discussionsupporting

confidence: 85%

The effects of tamoxifen and soy on dark neuron production in hippocampal formation after pentylenetetrazole-induced repeated seizures in rats

Ebrahimzadeh‐Bideskan

Ataei

Mansouri

et al. 2015

Pathophysiology

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“…Estradiol has mixed effects when administered acutely ranging from no effect, mild anticonvulsant to proconvulsant effects on seizures mainly depending whether physiological or supraphysiological doses have been used (Gevorkyan et al, 1989; Nicoletti et al, 1985; Velíšková et al, 2010). Nevertheless as mentioned above, besides the fact whether reports on estradiol effects show proconvulsant or anticonvulsant effects, studies generally agree that estradiol pretreatment significantly decreases status epilepticus-related mortality and severity of seizures (Ledoux et al, 2009; Scharfman et al, 2005; Velíšková et al, 2000; Woolley, 2000).…”

Section: Mechanism-based Differences Between Effects Of Estradiol Andmentioning

confidence: 99%

Sex and hormonal influences on seizures and epilepsy

Velı́šková

DeSantis

2013

Hormones and Behavior

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Epilepsy is the third most common chronic neurological disorder. Clinical and experimental evidence supports the role of sex and influence of sex hormones on seizures and epilepsy as well as alterations of the endocrine system and levels of sex hormones by epileptiform activity. Conversely, seizures are sensitive to changes in sex hormone levels, which in turn may affect the seizure-induced neuronal damage. The effects of reproductive hormones on neuronal excitability and seizure-induced damage are complex to contradictory and depend on different mechanisms, which have to be accounted for in data interpretation. Both estradiol and progesterone/allopregnanolone may have beneficial effects for patients with epilepsy. Individualized hormonal therapy should be considered as adjunctive treatment in patients with epilepsy to improve seizure control as well as quality of life.

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Modifying effect of estradiol and progesterone on epileptic activity of the rat brain

Cited by 13 publications

References 6 publications

Tamoxifen Mimics the Effects of Endogenous Ovarian Hormones on Repeated Seizures Induced by Pentylenetetrazole in Rats

Tamoxifen Mimics the Effects of Endogenous Ovarian Hormones on Repeated Seizures Induced by Pentylenetetrazole in Rats

The effects of tamoxifen and soy on dark neuron production in hippocampal formation after pentylenetetrazole-induced repeated seizures in rats

Sex and hormonal influences on seizures and epilepsy

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