Agonist-induced calcium and oxidative stress responses in endothelial cells.
[Ca(2+)](i) (cytosolic [Ca(2+)]) and OS (oxidative stress) were measured simultaneously in calf pulmonary artery endothelial cells using fura-2 and carboxy-2',7'-dichlorodihydrofluorescein. ATP stimulated a [Ca(2+)](i) increase that was followed a few seconds later by an increase in OS. Pre-exposure to 5 microM H(2)O(2) potentiated these responses to ATP. Elevating or removing extracellular Ca(2+) increased or reduced the [Ca(2+)](i) response to ATP and caused parallel changes in the OS response, suggesting that this response was a consequence of the [Ca(2+)](i) response. Inhibition of mitochondria with rotenone or antimycin A affected the responses but not in a manner that allowed a simple interpretation of the role of mitochondria. These data show an intimate connection between [Ca(2+)](i) and OS that can be modulated by low levels of exogenously applied OS, allowing the possibility of positive feedback.
D000255:Adenosine Triphosphate / Q000737:chemistry; D000818:Animals; D000968:Antimycin A / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002417:Cattle; D002460:Cell Line; D004396:Coloring Agents / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000473:pathology; D005452:Fluoresceins / Q000494:pharmacology; D016257:Fura-2 / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000494:pharmacology; D018384:Oxidative Stress; D011651:Pulmonary Artery / Q000473:pathology*; D017382:Reactive Oxygen Species; D012402:Rotenone / Q000494:pharmacology; D013997:Time Factors
D004396:Coloring Agents; D005452:Fluoresceins; D017382:Reactive Oxygen Species; D012402:Rotenone; C065013:2',7'-dichlorodihydrofluorescein; D000968:Antimycin A; D000255:Adenosine Triphosphate; D006861:Hydrogen Peroxide; D002118:Calcium; D016257:Fura-2