Chronic cold stress-induced alterations in brush border membrane composition and enzyme activities in rat intestine.

The effect of chronic cold stress on the composition and function of rat intestinal brush border membrane (BBM) was studied. Various lipid fractions from intestinal BBM viz. cholesterol (p < 0.01), phospholipids (p < 0.01), triglycerides (p < 0.05) and gangliosides (p < 0.05) were significantly reduced in cold stressed animals, as compared to controls. Analysis of membrane saccharide content revealed a significant increase in sialic acid (25%) and hexosamine (36%) contents and a reduction in fucose (19%) content in cold stressed rats. Determination of various enzyme activities in BBM showed significantly enhanced activities of alkaline phosphatase ( p < 0.01), lactase ( p < 0.001) and leucine aminopeptidase ( p < 0.001), whereas sucrase activity was reduced ( p < 0.05) under these conditions. The magnitude and site of these alterations across the crypt-villus axis varied from enzyme to enzyme. These findings suggest that chronic cold stress results in profound alterations in intestinal BBM. Altered structure and function of intestinal BBM may play a role in stress-induced derangements in gastrointestinal tract.