Details of True Calcium Absorption and Calcium Excretion into Feces in Female Rats during Growth
| Autor: | Shoji Yamada, Kazuo Harai, Tsuneyoshi Sano, Tomio Morohashi |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Calcium Isotopes
medicine.medical_specialty Biological Availability Medicine (miscellaneous) chemistry.chemical_element Calcium Biology Bone and Bones Intestinal absorption Bone remodeling Isotopes of calcium Excretion Feces Internal medicine Calcium flux medicine Animals Rats Wistar Calcium metabolism Nutrition and Dietetics Age Factors Urinary calcium Rats Calcium Dietary Endocrinology Intestinal Absorption chemistry Female |
| Zdroj: | Journal of Nutritional Science and Vitaminology. 47:52-56 |
| ISSN: | 1881-7742 0301-4800 |
| DOI: | 10.3177/jnsv.47.52 |
| Popis: | The details of calcium flux during growth were examined in female rats. Twenty-eight 53-d-old rats were equally divided into 4 groups. Rats were given a purified diet (0.5% Ca and 0.35% Pi) throughout the experiment. Calcium balance and 45Ca kinetics studies using an open two-compartment model were performed over a 3-d period when rats were 60 (control), 74 , 88 and 116 d old. A simple calcium balance study, using the last group, was carried out at the age of 102 d. Compared with the control group, true intestinal calcium absorption was significantly increased at 74 d, but then decreased in a time-dependent manner up to 116 d. The apparent intestinal calcium absorption began to decrease at 88 d, and decreased further with age. An increase in urinary calcium output was observed at 74 and 88 d in phase with calcium excretion into the intestine, and both variables returned to the control level at 116 d. Calcium into bone was decreased at 74 and 116 d. Calcium from bone similarly changed with Vo+ at 74 d: however the highest value was observed at 88 d. Thereafter, Vo- reached the control level at 116 d. Calcium balance rapidly decreased at 88, 102 and 116 d, but still remained positive. Calcium intake remained steady until 102 d, but was significantly decreased at the end of the experiment. The changes in calcium flux with age can be summarized as follows: 1) bone turnover decreased, calcium excretion into the urine and feces began to increase, and true intestinal calcium absorption increased, 2) apparent intestinal calcium absorption decreased, while calcium from bone and calcium excretion into the urine and feces increased, and 3) calcium intake and calcium into bone decreased. |
| Databáze: | OpenAIRE |
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