Effects of 3-aminopyridine-induced seizures on platelet eicosanoid synthesis.
Journal Title: Pharmacological Reports - Year 2008, Vol 60, Issue 3
Abstract
We investigated the influence of recurrent epileptic seizures on the arachidonic acid (AA) cascade in platelets and brain microvessels, using [(14)C]AA as a tracer substrate and chromatographic determination. The recurrent epileptic seizures of male Wistar rats were induced every second day with 3-aminopyridine (3-AP, 25 mg/kg ip) for two weeks. In the chronic 3-AP model, the earlier epileptic insults resulted in a decreased incidence of limbic seizures and higher survival rate at later administration of 3-AP. After 3-AP treatment, the formation of lipoxygenase products was unchanged, but the total amount of cyclooxygenase (COX) metabolites was decreased both in platelets and brain microvessels. The reduction in COX-mediated eicosanoid synthesis after recurrent seizures was due to the decreased synthesis of vasodilator and vasoconstrictor COX metabolites. In platelets, the 3-AP-treatment reduced the synthesis of vasodilator prostacyclin (PGI(2)), prostaglandin E(2) (PGE(2)) and 12-L-hydroxy-5,8,10-heptadecatrienoic acid (12-HHT), while the synthesis of prostaglandin D(2) (PGD(2)) remained unchanged. In isolated brain capillaries, the PGD(2), PGE(2) and 12-HHT synthesis was decreased after recurrent seizures. As for the vasoconstrictor COX metabolites, both platelets and brain microvessels synthesized significantly lesser amount of prostaglandin F(2alpha) (PGF(2alpha)) and thromboxane A(2) (TxA(2)) upon 3-AP administration. Our results indicate that platelets and isolated brain capillaries synthesize significantly lesser amount of COX metabolites after chronic 3-AP treatment. The decreased conversion of AA into different COX products may play a role in the neuroprotective/preconditional adaptation of the brain against subsequent seizures.
Authors and Affiliations
Gábor Csányi, Béla Kis, Arpád Gecse, Gyula Telegdy, Zoltán Szupera, László Vécsei, Magdolna Szente, István Leprán, Zsófia Mezei
Impact of early-life stress on the medial prefrontal cortex functions - a search for the pathomechanisms of anxiety and mood disorders.
Although anxiety and mood disorders (MDs) are the most common mental diseases, the etiologies and mechanisms of these psychopathologies are still a matter of debate. The medial prefrontal cortex (mPFC) is a brain structu...
Inhibitory effect of antidepressants on B16F10 melanoma tumor growth.
Background: Antidepressant drugs, like fluoxetine, a selective serotonin reuptake inhibitor, desipramine, a nonselective noradrenaline reuptake inhibitor, and mirtazapine, an antagonist of noradrenaline α2 auto- and hete...
Interleukin-13-induced activation of signal transducer and activator of transcription 6 is mediated by an activation of Janus kinase 1 in cultured human bronchial smooth muscle cells.
Background: The current study was carried out to identify the JAK molecule(s) that is involved in the IL-13-induced activation of STAT6 in cultured human bronchial smooth muscle cells (hBSMCs). Methods: Cultured hBSMCs w...
Systemic perfluorohexane attenuates lung injury induced by lipopolysaccharide in rats: the role of heme oxygenase-1.
Clinical trials with partial liquid ventilation demonstrate improvement in oxygenation, as well as some adverse side effects linked to the application of liquid perfluorocarbons (PFCs) during liquid ventilation. Thus, we...
Synthesis, anticonvulsant properties and 5-HT1A/5-HT2A receptor affinity of new N-[(4-arylpiperazin-1-yl)-propyl]-2-aza-spiro[4.4]nonane and [4.5]decane-1,3-dione derivatives.
A series of twenty new N-[(4-arylpiperazin-1-yl)-propyl]-2-aza-spiro[4.4]nonane- and [4.5]decane-1,3-dione derivatives were synthesized and their anticonvulsant activity was evaluated in maximal electroshock (MES) and sc...