Glycosylation of a novel member of the immunoglobulin gene superfamily expressed in rat carcinoma cell lines.

MAb E4 recognizes a 66-kDa glycoprotein, pE4, which is a member of the immunoglobulin gene superfamily. This protein is expressed at the cell surface in rat colon and mammary carcinomas, but only in trace amounts in normal adult rat tissues. Since expression of aberrant carbohydrate structures is often associated with malignant transformation, glycosylation of pE4 was analyzed.

Re-expression of thyroxine-binding globulin in post-weaning rats during protein or energy malnutrition.

Thyroxine-binding globulin, the highest affinity thyroid hormone binder of rat serum, was studied during 28 days of dietary protein restriction (6% protein vs 18% protein in isocaloric control diet) or energy restriction (60% intake of control diet). Studies were performed on male rats aged four weeks at the beginning of experiments: the animals had reached the ontogenic stage when the thyroxine-binding globulin had declined, after its high postnatal surge, to undetectable levels. Short-term administration (seven days) of one or the other restricted diet similarly induced resynthesis of the protein.

Regulation of hepatic transthyretin messenger RNA levels during moderate protein and food restriction in rats.

This study was designed to determine whether the decrease in serum transthyretin that occurs during food restriction results from gross energy reduction or from depressed protein or lipid intake and to examine the relationship between serum transthyretin and hepatic transthyretin mRNA during moderate protein or food deficiency. Groups of young rats were allowed free access to either a 18% (control) or a 6% protein diet (protein-restricted), or reduced intakes. The food-restricted groups received 60% of control intake from the control diet, a 40% protein-enriched diet, or a 40% lipid-enriched diet, for 28 d.

Changes in rat plasma apolipoproteins and lipoproteins during moderate protein deficiency: potential use in the assessment of nutritional status.

To test apolipoprotein sensitivity as protein deficiency markers, concomitant evolution of plasma apolipoproteins (apo) and usual nutritional markers (transthyretin, albumin, transferrin) were followed during a 28-d protein restriction in young male Wistar rats. In addition, plasma lipids and chemical composition of lipoproteins were assayed by d 28. The control and the deficient groups were fed 18% and 6% casein diets, respectively.

Failure of tryptophan deficiency to reduce specifically serum levels of transthyretin or albumin in rats.

Because transthyretin (TTR) is a tryptophan-rich molecule and a sensitive nutritional marker, tryptophan deficiency might markedly influence the circulating level of TTR. The effect of severe tryptophan (Trp) deficiency on serum TTR, as well as on albumin and transferrin levels, was studied in growing rats for 8 d. The animals were then refed a control diet for 12 d.