ABSTRACT
Fucose and sialic acid contents of intestinal microvillus membranes isolated from different animal species have been analysed. Expressed on protein basis, brush borders from fish contained considerably high amounts of sialic acid (298 +/- 16 nmole/mg protein), while rat, goat, sheep and guinea pig membranes showed 41-61 nmole/mg protein. Pig, frog, monkey rabbit and chicken membranes exhibited low levels of sialic acid (10-13 nmole/mg protein). Fucose content of the brush borders was quite high (203-212 nmole/mg protein) in frog and fish intestines. It was least in rabbit (54 +/- 3) and of intermediate levels (80-122 nmole/mg protein) in various other animal species analysed. Fucose to sialic acid molar ratio was less than 1 in fish microvillus membranes. In all other animal species, the ratio was however, greater than one and ranged between 1.65 and 15.20.