Fig. 3. Western blot analysis of mucus CA from guinea pig. For each analysis identical amounts of CA activity applied with the samples were: guinea pig colonic mucus with 0.87 U ml^-1 CA activity, isolated mucus CA with 5.3x10^-3 U ml^-1 CA activity. ^*Guinea pig CAI was applied at an amount of 0.87 U ml^-1 CA activity as a positive control for guinea pig mucus. Applying CA I at 5.8x10^-3 U ml^-1 as a control for isolated a mucus CA did not result in a visible band (not shown).