Fig. 2. Time course of volume changes in hepatocytes from goldfish, trout and rat, assessed by quantitative phase-contrast microscopy. (A) Total volume (V) changes of hepatocytes from goldfish exposed to 180 mosmol l^-1 medium at pH 7.45. Hepatocytes were isolated in collagenase-containing medium (filled circles) or in collagenase-free medium (open circles). (B) Relative volume (V_r) changes of hepatocytes of rat (triangles) and trout (squares) exposed to 180 mosmol l^-1 medium at pH 7.45 and of goldfish hepatocytes (circles) exposed to 180 mosmol l^-1 at pH 7.8. Values are means ± S.E.M. (N=4). Lines represent the empirical fit to data, with values of the parameters given in Table 1 and in the Results section.