title: Metoprine induced behavioral modifications and brain regional histamine increase in WAG/Rij and Wistar rats.
abstract: The effects of metoprine, an inhibitor of histamine N-methyltransferase, on open field activity and brain regional histamine (HA) content were examined in rats with mixed, absence and audiogenic, epilepsy (WAG/Rij-AGS), rats with audiogenic epilepsy (Wistar-AGS) and in non-epileptic control rats (Wistar-nAGS). HA content was increased by metoprine (20mg/kg, i.p.) in the cortex, striatum, thalamus, hypothalamus and hippocampus of the rats from all three tested groups. However, WAG/Rij rats showed a lower rate of metoprine-induced HA accumulation in the striatum and thalamus than Wistar rats. For the open field test, the main effect of metoprine (20mg/kg, i.p.) was a general increase of locomotor activity although distinctive features, such as hyperlocomotion and exaggerated sniffing, were characteristic for the epileptic rats (WAG/Rij-AGS and Wistar-AGS, respectively). Individual rats from all the groups showed stereotyped behavior of shuttle type and head bobbing. Electroencephalographic data obtained in WAG/Rij-AGS rats confirmed that metoprine-induced behavioral activation was accompanied by suppression of spike-wave discharges, the main hallmark of absence seizures. Taken together, these results show that inhibition of the histamine catabolism may induce motor activation of particular patterns in epileptic rats and provoke stereotyped behavior.
authors.affiliation: Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Butlerova Street 5a, Moscow, Russian Federation. samotaeva.irina@gmail.com
authors.forename: Irina S
authors.initials: IS
authors.lastname: Samotaeva
authors.forename: Lidiya M
authors.initials: LM
authors.lastname: Birioukova
authors.forename: Inna S
authors.initials: IS
authors.lastname: Midzyanovskaya
authors.forename: Galina D
authors.initials: GD
authors.lastname: Kuznetsova
authors.forename: Ara S
authors.initials: AS
authors.lastname: Bazyan
authors.forename: Leena
authors.initials: L
authors.lastname: Tuomisto
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001923:Brain Chemistry / Q000187:drug effects*; D004569:Electroencephalography / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D004827:Epilepsy / Q000235:genetics / Q000378:metabolism / Q000523:psychology; D004832:Epilepsy, Absence / Q000188:drug therapy / Q000235:genetics / Q000523:psychology; D020195:Epilepsy, Reflex / Q000523:psychology; D006120:Grooming / Q000187:drug effects; D006632:Histamine / Q000378:metabolism*; D008297:Male; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D011739:Pyrimethamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013239:Stereotyped Behavior / Q000187:drug effects
chemical_list: D004791:Enzyme Inhibitors; C006308:metoprine; D006632:Histamine; D011739:Pyrimethamine