Histamine-induced transients in [Ca2+]i. (A) Fluorescence ratio of 3 cells. Application of 50 μM fluvastatin without agonist followed by the application of histamine (50 μM) and fluvastatin again. Compared with histamine, fluvastatin causes no changes of [Ca2+]i. The very small waves of the baseline after the application of fluvastatin were not distinguishable from the normal baseline fluctuations which can always be observed when small changes of fluid flow or level in the experimental chamber are encountered (also see end of this record). (B) Records of the fluorescence ratios of 2 cells. Application of 50 μM histamine 3 times, during the second stimulation co-application of 50 μM fluvastatin. No specific effect caused by the application of fluvastatin was observed. The Ca2+ transients elicited by repeated histamine stimulations slightly decrease in amplitude. This is a normal phenomenon in endothelial cells and is not related to statin application.