High fat diets and mouse colon mucosal membranes: a centrifugation study.

Female Swiss mice were fed on a control diet (laboratory chow, 6% fat) or high fat diets (laboratory chow with added fat, principally corn oil, to produce a fat content of 16% or 23%). Homogenate of colon mucosa was fractionated by isopycnic banding on a linear sucrose gradient and the distribution of 5'-nucleotidase determined. Two main peaks were detected which we interpret as belonging to basolateral plasma membrane (BLPM) and brush borders. A high fat diet did not affect the relative sizes of the peaks or the median density of the BLPM peak but did significantly reduce the density of the brush border peak from 1.208 g/ml to 1.197 g/ml.