Figure 2. Hyposmotic swelling reduces the density of caveolae in the closed configuration.

Ventricular myocytes were exposed to isotonic or hypotonic solutions for 15 min. Representative electron micrographs of membrane sections from myocytes in isotonic (A.) and hypotonic (B.) conditions. Caveolae were recorded in both open (O) and closed (C) configurations (see Results). C. Mean data showing that exposure to hypotonic solution reduced the total number of caveolae through a reduction in the closed, but not open, state (* P<0.05 unpaired Student's t-test, n = 9–11 cells).