• Journal of Chest Surgery
• /
• v.41 no.4
• /
• pp.405-416
• /
• 2008

Background: Spinal cord ischemic injury during thoracic and thoracoabdominal aortic surgeries remains a potentially devastating outcome despite using various methods of protection. Neuronal voltage-dependent sodium channel antagonists are known to provide neuroprotection in cerebral ischemic models. This study was designed to compare the neuroprotective effects of phenytoin with those of hypothermia in a rabbit model of spinal cord ischemia. Material and Method: Spinal cord ischemia was induced in New Zealand white rabbits by means of infrarenal aortic cross clamping for 25 minutes. Four groups of 8 animals each were studied. The control group and the hypothermia group received retrograde infusion of saline only ($22^{\circ}C$, 2 mL/min); the normothermic phenytoin group and the hypothermicphenytoin group received retrograde infusion of 100 mg of phenytoin at different rectal temperatures ($39^{\circ}C$ and $37^{\circ}C$, respectively) during the ischemic period. The neurologic function was assessed at 24 and 72 hours after the operation with using the modified Tarlov criteria. The spinal cords were harvested after the final neurologic examination for histopathological examination to objectively quantify the amount of neuronal damage. Result: No major adverse effects were observed with the retrograde phenytoin infusion during the aortic ischemic period. All the control rabbits became severely paraplegic, Both the phenytoin group and the hypothermia group had a better neurological status than did the control group (p < 0.05). The typical morphological changes that are characteristic of neuronal necrosis in the gray matter of the control animals were demonstrated by means of the histopathological examination, whereas phenytoin or hypothermia prevented or attenuated these necrotic phenomena (p < 0.05). The number of motor neuron cells positive for TUNEL staining was significantly reduced, to a similar extent, in the rabbits treated with phenytoin or hypothermia. Phenytoin and hypothermia had some additive neuroprotective effect, but there was no statistical significance between the two on the neurological and histopathological analysis. Conclusion: The neurological and histopathological analysis consistently demonstrated that both phenytoin and hypothermia may afford significant spinal cord protection to a similar extent during spinal cord ischemia in rabbits, although no significant additive effects were noticed.

• Proceedings of the Korean Society of Toxicology Conference
• /
• 2001.10a
• /
• pp.195-195
• /
• 2001

The inhibitory potentials of TCAs (imipramine, desipramine, amitriptyline, and nortriptyline) on phenytoin p-hydroxylation and probe metabolic pathways of each CYP isoforms were evaluated from incubation studies of human liver microsomes and cDNA-expressed cytochrome P450s in vitro in order to understand the mechanism of drug interaction between TCAs and phenytoin, a substrate of CYP2C9 and CYP2C19. (omitted)

• 대한치주과학회:학술대회논문집
• /
• 1994.12a
• /
• pp.80-80
• /
• 1994

• Toxicological Research
• /
• v.14 no.3
• /
• pp.357-363
• /
• 1998

The teratogenic potential of the anticonvulsant drug phenytoin (PHT) has been well documented both in the human and in the experimental animals. However there are few reports on the effects of PHT on embryonic development in rats in vitro. The present study was performed to evaluate the teratogenic effects of PHT using whole-embryo culture system in rats. Sprague-Dawley rat embryos were explanted on gestational day (GD) 9.5 and cultured for 48 hrs in the immediately centrifuged and heat-inactivated rat serum containing 0,25,50, or $100{\mu}g$ PHT/mL. At the end of culture period the embryos were scored for morphological development according to the procedure of Van Maele-Fabry, and their total protein contents were determined. At 100 ${\mu}$g/mL of culture medium. PHT caused significant reduction in developmental score and protein content of embryos and a high incidence morphological abnormalities (100%). Characteristic malformations included altered yolk and embryonic circulation, craniofacial hypoplasia, neural tube schisis, branchial arch defects, abnormal ratation, and limb bud hypoplasia, among others. There were no adverse effects on embryonic growth and development at concentrations of 25 and 50 ${\mu}$g /mL of culture medium. The results indicated that the dysmorphogenic effect of PHT on cultured embryos is due to a direct interference with embryonic development.

• Korean Journal of Veterinary Research
• /
• v.34 no.4
• /
• pp.821-831
• /
• 1994

Phenytoin(PHT), a commonly prescribed anticonvulsant, has been known as a teratogen in experimental animals and human. However, PHT has strain-specific teratogenic effects for mice and human. Dimethyl sulfoxids(DMSO) has been known to antagonize the teratogenic effects of secalonic acid D, a toxic mold metabolite that has similar teratogenic effects to PHT. Therefore, this study was performed to examine the embryopathic effects of PHT in terms of treatment period and the antiteratogenic effect of DMSO in ICR mice. PHT(75mg/kg, BW) was administered intrapetitoneally on day 10, 10-11 and 10-12 of gestation with or without DMSO(2ml/kg, BW), and the fetal malformation was observed on day 18. Major malformation of fetuses treated with PHT on day 10, 10-11 and 10-12 of gestation was cleft palate, and the percentages of fetus with cleft palate were 14.5%, 31.7% and 51.7%, respectively. Also, there was a significant decrease of cleft palate from 51.7% in PHT alone group to 30.8% in PHT plus DMSO group. Our findings suggest that cleft palate is one of major malformation by PHT treatment in ICR mouse and DMSO has strong antiteratogenic effect.

• YAKHAK HOEJI
• /
• v.42 no.2
• /
• pp.196-204
• /
• 1998

The blood-brain barrier (BBB) of rats was modificated opening reversibly by infusing a hyperosmotic solution of arabinose (1.6 molal) into the right external carotid artery. Pre vious studies demonstrated that permeability was increased maxmmally in the first 15 min and remained slightly elevated at 1 hr. As control reference, saline was used. In the present study, to evaluate the effects of osmotic BBB opening on the BBB trasport according to hydrophilic or hydrophobic characteristics of drugs. And the differences of the uptakes of these compounds to right (treated osmotic opening) and left (untreated) hemispheres in same rats were compared each other following injection of 8 mCi per rat of $^{99m}Tc$-ethylene triamine pentaacetic acid (DTPA) as hydrophilic drug or 5mg/kg of phenytoin as hydrophobic drug mto the right external carotid artery of rats between two groups (1.6 molal arabinose vs saline). The uptakes of $^{99m}Tc$-DTPA and phenytoin in the right cerebral hemispheres were increased to about thirty three times and twice rather than those in the left cerebral heimspheres, respectively. And PAs (permeability X capillary surface area) were also increased from a control mean of 2.11${\times}10^{-4}$ (Untreated) to 6.98${\times}10^{-3}\;sec^{-1}$ (treated osmotic opening for $^{99m}Tc$-DTPA and 0.29 to 0.17 $sec^{-1}$ for phenytoin, respectively. From the results of present study, it is noted that osmotic opening of BBB is more effective in the brain delivery of hydrophilic drugs rather than that of hydrophobic drugs.

• 대한임상약리학회:학술대회논문집
• /
• 1999.12a
• /
• pp.32-32
• /
• 1999

• Advances in Traditional Medicine
• /
• v.7 no.1
• /
• pp.46-50
• /
• 2007

Callus cultures of Convolvulus microphyllus Sieb. was induced on Murashige and Skoog's medium supplemented with 2,4-dichloro phenoxy acetic acid, 6-benzyl adenine, indole acetic acid and kinetin (1 ppm each). Methanolic extracts of whole plant, leaf, stem and leaf and stem calli were tested for anticonvulsant activity against standard drug phenytoin using maximal electroshock model on mice. It was observed that the animals treated with methanolic extracts of stem callus, leaf callus and whole plant (200 mg/kg, oral) showed significant protection against tonic convulsions induced by transcorneal electroshock. Anticonvulsant activity of methanolic extract of stem callus was comparable to that of standard drug phenytoin.

• Proceedings of the Korea Environmental Mutagen Society Conference
• /
• 2002.05a
• /
• pp.47-47
• /
• 2002

• International Journal of Oral Biology
• /
• v.31 no.2
• /
• pp.33-43
• /
• 2006

Dysplasia-associated seizure disorders are markedly resistant to pharmacological intervention. Relatively little research has been conducted studying the effects of antiepileptic drugs(AEDs)on seizure activity in a rat model of dysplasia. We have used rats exposed to methylazoxymethanol acetate(MAM) in utero, an animal model featuring nodular heterotopia, to investigate the effects of AEDs in the dysplastic brain. Pilocarpine was used to induce acute seizure in MAM-exposed and age-matched vehicle-injected control animals. Field potential recordings were used to monitor amplitude and numbers of population spikes, and paired pulse inhibition in response to stimulation of commissural pathway. Two commonly used AEDs were tested: diazepam 5, 2.5 mg/kg; phenytoin 40, 60 mg/kg. Diazepam(DZP) and phenytoin(PHT) reduced the amplitude of population spike in control and MAM-exposed rats. However, the amplitude of population spike was nearly eliminated in control rats as compared to the MAM-exposed rats. Pharmaco-resistance was tested by measuring seizure latencies in awake rats after pilocarpine administration(320 mg/kg, i.p.) with and without pretreatment with AEDs. Pre-treatment with PHT 60 mg prolonged seizure latency in control rats, but not in MAM-exposed animals. The main findings of this study are that acute seizures initiated in MAM-exposed rats are relatively resistant to standard AEDs assessed in vivo. These data suggest that animal model with cortical dysplasia can be used to screen the effects of potential AEDs.