QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Muramatsu, K. Articles by Ashida, K. Search for Related Content PubMed PubMed Citation Articles by Muramatsu, K. Articles by Ashida, K.

Dietary Protein Level and the Turnover Rate of Tissue Proteins in Rats

Laboratory of Food and Nutrition, Department of Agricultural Chemistry, Nagoya University, Anjo, Aichi, Japan

The effect of varying levels of dietary protein on the turnover rates of the combined proteins of several tissues in rats was studied. The rate of loss of isotope from the proteins of each tissue labeled following injection of DL-methionine-S³⁵ was measured in young rats fed diets containing zero to 60% of casein for 3 weeks. The tissues examined were liver, kidney, plasma, spleen, intestinal mucosa, heart, muscle and testis. The apparent turnover rate of the proteins of each tissue was calculated from the slope of the response curve of the specific activity obtained plotting against the first, fourth and seventh day following injection of labeled methionine. Among these tissue proteins, the turnover rates of intestinal mucosa, plasma, kidney, spleen and liver proteins were affected by the protein level in the diet, and were increased with increments of the protein level. However, no further increase was observed by increasing the protein level above 25 or 40%. The response curves of the changes in turnover rates of these proteins plotted against the protein level were similar to that of body weight plotted in a similar way.

Manuscript received 2 August 1963.