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 Suzuki, H. Articles by Fuwa, H. Search for Related Content PubMed PubMed Citation Articles by Suzuki, H. Articles by Fuwa, H.

Comparison of Effects of Dietary Calcium and Magnesium Depletion on Renal Glucose-6-Phosphatase Activity of Rats Fed High Protein and High Carbohydrate Diets

Laboratory of Nutritional Biochemistry, Department of Agricultural Chemistry, Faculty of Agriculture, Nagoya University, Nagoya, Japan

In order to determine the relationship between renal gluconeogenesis and calcium status of the body, the effects of low levels of dietary calcium and magnesium on growth rate, food intake, serum and renal calcium concentrations and activities of hepatic and renal glucose-6-phosphatase (G6Pase) of rats were investigated under the conditions of feeding a high protein or a high carbohydrate diet. Calcium depletion caused significant decreases in the growth rate and food intake of rats fed the high protein diet, while in rats fed the high carbohydrate—low calcium diet no significant changes were observed. Feeding the low magnesium diets caused marked decreases both in the growth rate and food intake of rats compared with those of corresponding control dietary groups. The activity of renal G6Pase was increased remarkably by feeding the low calcium diets, while the hepatic activity of the enzyme did not show any significant change in either of these dietary groups. The stimulative effects of both high dietary protein and low dietary calcium on the activity of renal G6Pase were additive. On the other hand, magnesium depletion produced lower activities of renal G6Pase than those of rats fed the corresponding control diets on a gram wet weight basis. Levels of serum calcium tended to decrease in groups fed the low calcium diets, while those of groups fed the low magnesium diets tended to increase compared with those of corresponding control dietary groups. Higher susceptibility of rats fed the high protein diet to calcium depletion compared with rats fed the high carbohydrate diet led to the consideration that the effect of the high protein diet on the activity of renal G6Pase might be related to changes in calcium status of the body.

KEY WORDS: • high protein diet • renal glucose-6-phosphatase • calcium depletion

¹ Present address: Laboratory of Food Chemistry, Department of Food Science, Faculty of Agriculture, Kagawa University, Miki-cho, Kagawa-ken, Japan.

² Present address: Laboratory of Food Chemistry, Department of Food and Nutrition, Faculty of the Science of Living, Osaka City University, Sugimotocho, Sumiyoshi-ku, Osaka, Japan.

Manuscript received 5 May 1972.