Avtor/Urednik		Simčič, Saša
Naslov		Znotrajcelični kalcij in sproženje oksidativnega izbruha človeških nevtrofilnih granulocitov
Tip		monografija
Kraj izdaje		Ljubljana
Založnik		Medicinska fakulteta
Leto izdaje		2002
Obseg		str. 113
Jezik		slo
Abstrakt		The cytosolic free calcium (Ca2+) is responsible for controlling numerous cellular processes. However, the precise role of the cytosolic free Ca2+ concentration ((Ca2+)c) and its relationship to other signalling components in the signal transduction from chemoattractant (e.g. N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP) or C5a) receptors, receptors involved in the phagocytosis of the opsonized zymosan A and IL-12 receptor to the NADPH-oxidase of human neutrophil granulocytes is still poorly understood. In this study, we have used thapsigargin, an inhibitor of the Ca2+-ATPase of intracellular Ca2+ stores, as a tool to alternatively manipulate Ca2+ release from intracellular stores or Ca2+ influx across the plasma membrane. We thereby temporarily separated the Ca2+ signal from other signals generated by an agonist and analysed the. consequential oxidative burst measured as luminol-enhanced chemiluminescence. Under all conditions investigated, the extent of fMLP-, C5a- and IL-12-induced oxidative burst was critically depending on (Ca2+)c elevation measured by fluo-3 fluorescence probe and a flow cytometer. All three agonists were unable to activate the oxidative burst without (Ca2+)c elevation. The electroporation-induced (Ca2+)c elevation or the thapsigargin-induced Ca2+ influx in the absence of the agonist did not or only weakly activated the oxidative burst. Other putative signals generated by the agonist did not activate the oxidative burst by itself, but acted in sinergy with (Ca2+)c elevation. In contrast, an increase in (Ca2+)c was not required for opsonized zymosan A-induced oxidative burst. When cells with thapsigargin-depleted Ca2+ stores were exposed to the phagocytic stimulus in the Ca2+-free medium they still produced a significant amount of the superoxide. (Abstract truncated at 2000 characters).
Deskriptorji		GRANULOCYTES CALCIUM RESPIRATORY BURST THAPSIGARGIN COMPLEMENT 5A CHEMILUMINESCENCE FLOW CYTOMETRY ELECTROPORATION INTERLEUKIN-12 N-FORMYLMETHIONINE LEUCYL-PHENYLALANINE CYTOSOL NADPH OXIDASE IGG