Effect of high-fat diet on phosphorus absorption
Kawamoto, Keisuke University of Shizuoka
Sakuma, Masae University of Shizuoka|Sugiyama Jogakuen University
Tanaka, Sarasa University of Hyogo
Nakao-Muraoka, Mari University of Tokushima
Niida, Yuki University of Tokushima
Nakamatsu, Yurino University of Shizuoka
伊藤, 美紀子 University of Hyogo
新井, 英一 University of Shizuoka
Serum phosphorus levels
Objective: Dietary carbohydrate/fat ratio may affect phosphorus metabolism because both calcium and phosphorus are regulated by similar metabolic mechanisms, and a high-fat diet (HF) induces deleterious effects on the absorption of dietary calcium. We hypothesized that the HF induces an increase in phosphorus absorption; therefore, this study aimed to evaluate the effects of differences in the quantity and quality of dietary fat on phosphorus metabolism over the short and long term.
Research Methods & Procedures: Eighteen 8-week-old Sprague-Dawley male rats were fed an isocaloric diet containing varied carbohydrate/fat energy ratio and sources of fat (control diet [Control], HF, and high saturated-fat diet [HF-SFA]). At 3 days and 7 weeks after the allocation and initiation of the test diets, feces and urine were collected and used for phosphorus and calcium measurement.
Results: The fecal phosphorous concentration (F-Pi) was lower in the HF-SFA group than in the other two groups; however, the urine phosphorus concentration (U-Pi) was significantly higher in the HF-SFA group than the other two groups when the rats were fed over the short (p<0.01) and long term (p<0.01 vs Control group, p<0.05 vs HF group). There were no significant differences in type-IIa sodium-phosphate cotransporter (NaPi-2a) and type-IIc sodium-phosphate cotransporter (NaPi-2c) mRNA expression, which are renal phosphate transport-related genes; however, the expression of type-IIb sodium-phosphate cotransporter (NaPi-2b) and type-III sodium-phosphate cotransporter (Pit-1) mRNA in the duodenum was higher in the HF and HF-SFA groups than in the Control group (p<0.05), although there were no significant differences in these in the jejunum.
Conclusions: Our results indicated that HF, particularly HF-SFA, increases intestinal phosphate absorption compared with Control.
© 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
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