We have demonstrated previously that activation of either the ETA or ETB receptor can induce acute electrographic seizures following the intrahippocampal infusion of endothelin-1 (ET-1) in immature (P12) rats. We also demonstrated that activation of the ETA receptor is associated with marked focal ischemia, while activation of the ETB receptor is not. Exploring the mechanisms underlying seizures induced by these two ET-1 receptor interactions can potentially provide insight into how focal ischemia in immature animals produces seizures and whether ischemiarelated seizures differ from seizures not associated with ischemia. To explore these seizure mechanisms we used microdialysis to determine biomarkers associated with seizures in P12 rats following the intrahippocampal infusion of two different agents: (1) ET-1, which activates both the ETA and ETB receptors and causes focal ischemia and (2) Ala-ET-1, which selectively activates only the ETB receptor and does not cause ischemia. Our results show that seizures associated with combined ETA and ETB receptor activation (and ischemia) have a different temporal distribution and microdialysis profile from seizures associated with ETB activation alone (and without ischemia). Seizures with combined activation peak within the first hour after infusion and the microdialysis profile is characterized by a significant increase in the ratio of glutamic acid to GABA. By contrast, seizures with activation of only the ETB receptor peak in the second hour after infusion and microdialysis shows a significant increase in the ratio of leukotriene B4 to prostaglandin E2. These findings suggest that ischemia-related seizures in immature animals involve an imbalance of excitation and inhibition, while non-ischemiarelated seizures involve an inflammatory process resulting from an excess of leukotrienes.

• MeSH
• endotelin-1 toxicita   MeSH
• hipokampus účinky léků   metabolismus   MeSH
• ischemie mozku chemicky indukované   metabolismus   MeSH
• krysa rodu rattus MeSH
• potkani Wistar MeSH
• receptor endotelinu A metabolismus   MeSH
• receptor endotelinu B metabolismus   MeSH
• záchvaty chemicky indukované   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Clinical and experimental studies indicate that muscarinic acetylcholine receptors are potential pharmacological targets for the treatment of neurological diseases. Although these receptors have been described in human, bovine and rat cerebral microvascular tissue, a subtype functional characterization in mouse brain endothelium is lacking. Here, we show that all muscarinic acetylcholine receptors (M1-M5) are expressed in mouse brain microvascular endothelial cells. The mRNA expression of M2, M3, and M5 correlates with their respective protein abundance, but a mismatch exists for M1 and M4 mRNA versus protein levels. Acetylcholine activates calcium transients in brain endothelium via muscarinic, but not nicotinic, receptors. Moreover, although M1 and M3 are the most abundant receptors, only a small fraction of M1 is present in the plasma membrane and functions in ACh-induced Ca2+ signaling. Bioinformatic analyses performed on eukaryotic muscarinic receptors demonstrate a high degree of conservation of the orthosteric binding site and a great variability of the allosteric site. In line with previous studies, this result indicates muscarinic acetylcholine receptors as potential pharmacological targets in future translational studies. We argue that research on drug development should especially focus on the allosteric binding sites of the M1 and M3 receptors.

• MeSH
• acetylcholin farmakologie   MeSH
• alosterické místo MeSH
• cévní endotel cytologie   metabolismus   MeSH
• endoteliální buňky účinky léků   metabolismus   MeSH
• mikrocévy metabolismus   MeSH
• mozek krevní zásobení   MeSH
• myši inbrední BALB C MeSH
• nikotinové receptory metabolismus   MeSH
• receptory muskarinové chemie   metabolismus   MeSH
• vápníková signalizace účinky léků   MeSH
• vazebná místa MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Během vývoje mozku dochází v průběhu dospívání k mnoha významným změnám na úrovni molekulární, buněčné i orgánové. Přestože výzkum v této oblasti probíhá již řadu desetiletí, nejsou zcela objasněné některé mechanizmy a probíhající vývojové změny. Mikrodialýza (MD) v kombinaci s vysokoúčinnou kapalinovou chromatografíí a hmotnostní spektrometrií (HPLC/MS) umožňuje monitorování tkáňové biochemie, t.j. metabolomické mapování, v nezralém mozku téměř v reálném čase. Úspěšná aplikace kombinace těchto dvou metod má vysoký a unikátní potenciál rozšířit znalosti v oblasti fyziologie a patofyziologie nezralého mozku a dokonce pomoci vyvinout účinnou léčbu mnoha dětských nemocí.

In early developmental stages of brain, many maturational processes on molecular, cellular and organ level take place. Although many years of research were dedicated to this topic, the clarification of numerous mechanisms and their roles in later development is still lacking. Combination of microdialysis (MD) and high performance liquid chromatography combined with mass spectrometry (HPLC/MS) represents a unique possibility for the monitoring of tissue biochemistry and metabolomic mapping in immature brain in almost real -time condition. Hence, it has a great potential to broaden our knowledge in physiology and pathophysiology of immature brain and can help to develop effective treatment of many infant diseases.

• Klíčová slova
• nezralý mozek,
• MeSH
• hmotnostní spektrometrie MeSH
• lidé MeSH
• metabolomika * MeSH
• mikrodialýza * MeSH
• mozek * metabolismus   růst a vývoj   MeSH
• novorozenec nedonošený MeSH
• novorozenec MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Check Tag
• lidé MeSH
• novorozenec MeSH
• Publikační typ
• práce podpořená grantem MeSH