Figure 2. Adenosine inhibits the osmotic swelling of Müller cell somata in freshly isolated retinal slices from wild-type mice. The cross-sectional area of the somata was measured after a 4 min perfusion of the slices with a hypoosmolar solution (in the absence and presence of 1 mM barium chloride, as indicated), and are expressed in percent of the soma size measured before hypotonic challenge (100%). A: The swelling-inhibitory effect of 10 µM adenosine (Ade) was prevented in the presence of 100 nM DPCPX, a selective antagonist of adenosine A₁ receptors. B: The swelling-inhibitory effect of 100 µM triamcinolone acetonide (Triam) was abrogated by 100 nM DPCPX, a A₁ receptor blocker. C: The cell-permeable calcium chelator BAPTA/AM (100 µM) did not reverse the swelling-inhibitory action of 10 µM adenosine. The swelling of Müller cells was abrogated in the presence of a cAMP-enhancing cocktail containing 100 µM pCPT-cAMP, 10 µM forskolin, and 100 µM IBMX. D: The effect of 10 µM adenosine was prevented in the presence of 10 µM clofilium, a potassium channel blocker, and 100 µM NPPB, a chloride channel blocker. Data are mean (±SEM) soma areas (n=7–12 cells per bar). Significant differences versus control (the asterisk indicates a p<0.001). Significant swelling-inhibitory effects (the solid circle indicates a p<0.001). Significant inhibition of the agonist effects (the open circle indicates a p<0.001).