Figure 3. NOS inhibition with LNNA does not increase the cytosolic Ca²⁺ concentration in smooth muscle cells of the SMA.

Male and female SMAs were pressurized at 60 cmH₂O and superfused with PSS to which 10 µM LNNA was added. Changes in the global cytosolic Ca²⁺ concentration were measured as fluo4 fluorescence intensity. A) Superimposed image of laser-scanning bright-field image (grey scale) and a fluorescence image of a pressurized SMA loaded with fluo4 (green). Note that fluorescence was emitted solely from smooth muscle cells. Scale bar  = 10 µm. B) Changes in global cytosolic Ca²⁺ concentration. Numbers next to the error bars represent the number of SMA segments. No significant differences were observed.