Modulation of intestinal calcium and phosphate transport in young goats fed a nitrogen- and/or calcium-reduced diet
| Autor: | Kristin Elfers, Alexandra S. Muscher-Banse, Mirja R. Wilkens, Gerhard Breves |
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| Rok vydání: | 2015 |
| Předmět: |
Male
medicine.medical_specialty Calcitriol Nitrogen Medicine (miscellaneous) chemistry.chemical_element Calcium Calcitriol receptor Intestinal absorption Phosphates Internal medicine medicine Animals Intestinal Mucosa Nutrition and Dietetics Ussing chamber Chemistry Goats Animal Feed Diet Intestines Endocrinology Intestinal Absorption Plasma membrane Ca2+ ATPase Flux (metabolism) Homeostasis medicine.drug |
| Zdroj: | British Journal of Nutrition. 114:1949-1964 |
| ISSN: | 1475-2662 0007-1145 |
| DOI: | 10.1017/s000711451500375x |
| Popis: | Feeding ruminants a reduced N diet is a common approach to reduce N output based on rumino-hepatic circulation. However, a reduction in N intake caused massive changes in Ca and inorganic phosphate (Pi) homoeostasis in goats. Although a single dietary Ca reduction stimulated intestinal Ca absorption in a calcitriol-dependent manner, a concomitant reduction of Ca and N supply led to a decrease in calcitriol, and therefore a modulation of intestinal Ca and Pi absorption. The aim of this study was to examine the potential effects of dietary N or Ca reduction separately on intestinal Ca and Pi transport in young goats. Animals were allocated to a control, N-reduced, Ca-reduced or combined N- and Ca-reduced diet for about 6−8 weeks, whereby N content was reduced by 25 % compared with recommendations. In Ussing chamber experiments, intestinal Ca flux rates significantly decreased in goats fed a reduced N diet, whereas Pi flux rates were unaffected. In contrast, a dietary Ca reduction stimulated Ca flux rates and decreased Pi flux rates. The combined dietary N and Ca reduction withdrew the stimulating effect of dietary Ca reduction on Ca flux rates. The expression of Ca-transporting proteins decreased with a reduced N diet too, whereas Pi-transporting proteins were unaffected. In conclusion, a dietary N reduction decreased intestinal Ca transport by diminishing Ca-transporting proteins, which became clear during simultaneous N and Ca reduction. Therefore, N supply in young ruminant nutrition is of special concern for intestinal Ca transport. |
| Databáze: | OpenAIRE |
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