Pig and human colonic cellular homogenates, respective LMVs and pig colonic BLMV (control) were treated as described in Figure 1. Lane a, pig colonic cellular homogenate; lane b, pig colonic LMV; lane c, human colonic cellular homogenate; lane d, human colonic LMV; lane e, pig colonic BLMV. In BLMV (lane e), bands corresponding to 95 kDa, the α-subunit and 40 kDa, the β-subunit of Na+-K+-ATPase (Tarpley et al. 1995) are concentrated compared with the original cellular homogenate (lane a). In LMV, sample levels of Na+-K+-ATPase are negligible.