Regulation of Hepatic Transthyretin Messenger RNA Levels during Moderate Protein and Food Restriction in Rats

Abstract

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. Serum transthyretin concentrations were lower in all experimental groups on d 7 relative to the control group. Control values were reached only in the protein-restricted group by d 14. The low serum transthyretin levels, which were similar in the food-restricted groups, likely resulted from gross energy restriction. Hepatic transthyretin mRNA levels were determined in the control, protein-restricted and food-restricted groups. They were unchanged relative to controls in the protein-restricted group but declined moderately in the food-restricted group on d 7 and 14, before returning to control values by d 28. Thus, the changes in liver transthyretin mRNA levels could partially explain the changes in serum transthyretin in food-restricted rats.

Assessment of Transthyretin Combined With Mini Nutritional Assessment on Admission Provides Useful Prognostic Information in Patients With Acute Decompensated Heart Failure

“…Thus, blood TTR concentrations can serve as a marker for current hepatocyte protein synthesis. 16) If protein intake falls below 60% of the required amount, 14 days later blood TTR concentration declines, 35) which often makes this a simple marker for nutritional status. However, TTR is a marker indicating the deterioration of general condition caused by various influences, including malnutrition and inflammation.…”

Gastric Bypass is not Associated with Protein Malnutrition in Morbidly Obese Patients

“…Transthyretin seems to be more sensitive to calorie reduction than protein reduction [25], especially in obese persons [26]. Therefore, transthyretin is both the signature of calorie restriction (i.e., weight loss) and an indicator of future complications [27].…”

Prognostic importance of serum CRP, prealbumin, and transferrin levels in patients with advanced stage esophageal cancer

“…[17] In experimental studies, a decrease in prealbumin production after 14 days of consuming a diet that provides only 60% of the daily protein need has been observed. [18] Prealbumin production can return to normal levels within 4-8 days with adequate nutrition. [19] Therefore, prealbumin is considered to be the best indicator for nutritional status.…”