Effects of high-glucose and high-fat diets on concanavalin A binding to rat liver plasma membranes and on the amount and pattern of their glycoprotein carbohydrates.

Abstract

Purified liver plasma membranes were prepared from rats fed a high-fat, carbohydrate-free diet or a high-glucose, fat-free diet. Membranes from rats fed the high-fat diet bound significantly less 125I-labeled concanavalin A (Con A) than did those from rats fed the fat-free diets. The magnitude of the binding difference increased with increasing concentrations of Con A. Neither association nor dissociation rates of the lectin-receptor complex was affected by diet. The extent of degradation of Con A by liver plasma membrane preparations from rats fed either diet was the same. Chemical analysis of delipidated liver plasma membrane showed that membranes prepared from high-fat diet-adapted rats had significantly lower values for all carbohydrate components measured with the exception of galactose. The results indicate that, in liver cells, a change in plasma membrane glycoproteins is part of the complex adaptation to altered diet composition.