Effects of histamine on oxidative burst in phagocytes

• Autoři: ČÍŽ Milan; VAŠÍČEK Ondřej; LOJEK Antonín
• Rok publikování: 2013
• Druh: Konferenční abstrakty
• Popis: Histamine exerts the capacity to influence the activity of immune cells including phagocytes and plays a pivotal role in inflammatory processes which are a complex network of cellular and humoral events. Since oxidative burst linked with the production of reactive oxygen species is a principal functional manifestation of activated phagocytes, the effects of histamine receptor agonists and antagonists on the oxidative burst of phagocytes was studied. The effects of H1-antihistamines of the 1st generation and the 2nd generation on the respiratory burst of phagocytes were investigated. Reactive oxygen species generation in phagocytes was measured using luminol-enhanced chemiluminescence. The antioxidative properties of drugs in cell-free systems were detected spectrophotometrically, luminometrically, and fluorimetrically. The majority of tested H1-antihistamines exhibited a significant inhibitory effect on the chemiluminescence activity of phagocytes. H1-antihistamines did not show significant scavenging properties against superoxide anion and hydroxyl radical, thus this could not contribute to the inhibition of chemiluminescence. It was concluded that the effects observed in the tested H1-antihistamines are not mediated exclusively via H1-receptor pathway or by direct antioxidative properties. A role of well characterized histamine H1 receptors was further compared to that of recently discovered H4 receptor. The effects of histamine and its specific H4R agonists on reactive oxygen species generation in phagocytes were investigated. All studied compounds significantly decreased the chemiluminescence response in phagocytes in a dose-dependent manner, whereas none of them had any antioxidant potential against reactive oxygen species. Nevertheless, it remains to be resolved whether this inhibition was mediated via the H4R or other receptor types.