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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Adenosine Triphosphate, Anesthetics, Inhalation, Animals, Bradykinin, Calcium, Cattle, Cells, Cultured, Cytoplasm, Endothelium, Vascular, Enflurane, Halothane, Isoflurane.
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Do volatile anesthetics affect calcium mobilization in bovine endothelial cells? Context: The site where volatile anesthetics inhibit endothelium-dependent, nitric oxide-mediated vasodilation is unclear. To determine whether anesthetics could limit endothelium-dependent nitric oxide production by inhibiting receptor-mediated increases in cytosolic Ca2+, experiments were performed to see if the inhalational anesthetics halothane, isoflurane, and enflurane affect intracellular Ca2+ ([Ca2+]i) transients induced by the agonists bradykinin and adenosine triphosphate in cultured bovine aortic endothelial cells. Bovine aortic endothelial cells, which had been loaded with the fluorescent Ca2+ indicator Fura-2, were added to medium preequilibrated with volatile anesthetic (1.25% and 2.5% for isoflurane, 1.755 and 3.5% for enflurane, and 0.75% and 1.5% for halothane). In Ca(2+)-containing medium, intracellular Ca2+ transients were elicited in response to bradykinin (10 nM and 1 microM) or adenosine triphosphate (1 microM and 100 microM). Both bradykinin and adenosine triphosphate triggered a rapid rise to peak [Ca2+]i followed by a gradual decline to a plateau above the resting level. Although basal [Ca2+]i was unaltered by the anesthetics, both halothane and enflurane, in a dose-dependent manner, depressed the peak and plateau of the [Ca2+]i transient elicited by 10 nM bradykinin, whereas isoflurane had no effect. When [Ca2+]i transients were elicited by 1 microM bradykinin, halothane (1% and 5%) did not alter peak and plateau levels. Halothane and enflurane also decreased [Ca2+]i transients evoked by 1 microM and 100 microM adenosine triphosphate, whereas isoflurane also had no effect in this setting.
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Halothane and enflurane, but not isoflurane, inhibit bradykinin- and adenosine triphosphate-stimulated Ca2+ transients in endothelial cells. Limitations of Ca2+ availability to activate constitutive endothelial nitric oxide synthase could allow for part, but not all, of the inhibition of endothelium-dependent nitric oxide-mediated vasodilation by inhalational anesthetics. Final Decision: yes