RESPONSES OF PLASMA FIBRONECTIN TO THE CHANGES OF DIETARY-PROTEIN LEVELS IN RATS

In this study, the plasma fibronectin was evaluated as a nutritional m arker in protein- and protein-energy malnourished rats in comparison w ith plasma prealbumin, albumin, and total protein. The plasma fibronec tin was determined by nephelometric assay based on the interaction of an antigen and antibody. The rats were subjected to three diets, conta ining 20, 5, and 0% casein, respectively, for 5 wk except in the last 2 wk, the rats on the 0% casein diet were re-fed on a 20% casein diet. The results showed that in the rats on a 5% casein diet (protein maln ourished), the plasma fibronectin concentration rose significantly in the early stage and normalized thereafter. In the rats subjected to a 0% casein diet (protein-energy malnourished), the plasma fibronectin c oncentration did not decline quickly in response to protein depletion, compared with the plasma prealbumin, albumin, and total protein conce ntrations. Following the re-feeding of a 20% casein diet in the last 2 wk, the plasma fibronectin concentration was restored earlier than ot her plasma protein concentrations: No significant change in plasma fib ronectin concentration was found in the rats receiving a 20% casein di et (control) over the 5 wk feeding period. It is concluded that plasma fibronectin may not be a suitable marker for protein or protein-energ y malnutrition, though it is a sensitive index for nutritional rehabil itation. (C) Elsevier Science Inc. 1997.