Figure 4. Cyclic GMP (cGMP) imaging in vessels of a retina acutely isolated from SM22-cGMP indicator with an EC₅₀ of 500 nmol/L (cGi500) mice.

A, Distribution of sensor fluorescence indicates mosaic expression in the vascular smooth muscle cells (VSMCs) of retinal vessels. B, On superfusion of 2-(N,N-diethylamino)-diazenolate-2-oxide diethylammonium salt (DEA/NO; 1 or 10 µmol/L), clear cGMP increases can be detected in these vessels. Responses of n=11 fluorescent regions outlined in white in A were measured, corrected with adjacent background regions (Bg1–3), and then averaged. Data shown are mean±SEM. Scale bar, 100 µm. Representative results from ≥4 experiments with independent tissue samples are shown.