title: Effect of prolonged phenytoin administration on rat brain gene expression assessed by DNA microarrays.
abstract: Preliminary clinical trials have recently shown that phenytoin, an antiepileptic drug, may also be beneficial for treatment of bipolar disorder. To examine molecular mechanisms of action of phenytoin as a potential mood stabilizer, DNA microarrays were used to study the effect of phenytoin on gene expression in the hippocampus and frontal cortex of Sprague-Dawley rats. While our particular interest is in bipolar disorder, this is the first DNA microarray study on the effect of phenytoin in brain tissue, in general. As compared with control rats, treated rats had 508 differentially expressed genes in the hippocampus and 62 in the frontal cortex. Phenytoin modulated the expression of genes which may affect neurotransmission, e.g. glutamate decarboxylase 1 (Gad1) and gamma-aminobutyric acid A receptor, alpha 5 (Gabra5). Phenytoin also exerted an effect on neuroprotection-related genes, namely the survival-promoting and antioxidant genes v-akt murine thymoma viral oncogene homolog 1 (Akt1), FK506 binding protein 12-rapamycin associated protein 1 (Frap1), glutathione reductase (Gsr) and glutamate cysteine ligase catalytic subunit (Gclc). The expression of genes potentially associated with mechanisms of mood regulation such as adenylate cyclase-associated protein 1 (Cap1), Glial Fibrillary Acidic Protein (Gfap) and prodynorphin (Pdyn) was also altered. Some of the above genes are regarded as targets of classical mood stabilizers and their modulation supports the clinical observation that phenytoin may have mood-stabilizing effects. The results may provide new insights regarding the mechanism of action of phenytoin and genes found differentially expressed following phenytoin administration may play a role in the pathophysiology of either bipolar disorder or epilepsy.
authors.affiliation: Department of Experimental Pathology, Medical Biotechnology, Infectious Diseases and Epidemiology, University of Pisa, Italy.
authors.forename: Veronica
authors.initials: V
authors.lastname: Mariotti
authors.forename: Erika
authors.initials: E
authors.lastname: Melissari
authors.forename: Shirly
authors.initials: S
authors.lastname: Amar
authors.forename: Angela
authors.initials: A
authors.lastname: Conte
authors.forename: Robert Haim
authors.initials: RH
authors.lastname: Belmaker
authors.forename: Galila
authors.initials: G
authors.lastname: Agam
authors.forename: Silvia
authors.initials: S
authors.lastname: Pellegrini
mesh_terms: D000818:Animals; D018692:Antimanic Agents / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000188:drug therapy*; D001835:Body Weight; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D004195:Disease Models, Animal; D005625:Frontal Lobe / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects*; D006624:Hippocampus / Q000187:drug effects; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D010672:Phenytoin / Q000627:therapeutic use*; D025341:Principal Component Analysis; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D018692:Antimanic Agents; D010672:Phenytoin