Figure 7. The hypotonic increase of ouabain binding depends on the integrity of microfilaments.

Experimental protocol similar to that used in the experiment depicted in Fig. 3B, except that it was performed in the presence of 10 μm Lat-B. The increases in ouabain binding promoted by reducing the tonicity from π= 1 to π= 0.5 (n = 8 paired muscles) and from π= 2 to π= 1 (n = 8 paired muscles) were virtually absent in the presence of this microfilament-disrupting agent (compare with data in Fig. 3A and B). The inset shows that Lat-B does not affect per se the ouabain binding (n = 8 paired muscles).