Increased calcium intake reduces plasma cholesterol and improves vasorelaxation in experimental renal failure

2003 ◽  
Vol 285 (5) ◽  
pp. H1882-H1889 ◽  
Author(s):  
Pasi Jolma ◽  
Peeter Kööbi ◽  
Jarkko Kalliovalkama ◽  
Mika Kähönen ◽  
Meng Fan ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Renal Failure ◽  
Parathyroid Hormone ◽  
Calcium Intake ◽  
Plasma Cholesterol ◽  
Plasma Phosphate ◽  
Plasma Total Cholesterol ◽  
Calcium Diet ◽  
High Calcium ◽  
High Calcium Diet

Chronic renal failure (CRF) is associated with abnormal lipid metabolism and high prevalence of vascular complications. Calcium salts are commonly used in CRF as phosphate binders. Increased calcium intake may also lower plasma cholesterol and beneficially influence vascular tone. Therefore, we investigated the influence of increasing dietary calcium from 0.3% to 3.0% for 8 wk after 5/6 nephrectomy (NTX) on plasma cholesterol and mesenteric resistance vessel tone in male Sprague-Dawley rats. The groups were Sham, Sham-Calcium, NTX, and NTX-Calcium ( n = 10–11). Blood pressure was modestly elevated after NTX, whereas the plasma creatinine, urea nitrogen, phosphate, and parathyroid hormone levels were clearly increased. The high-calcium diet suppressed plasma phosphate and parathyroid hormone but was without effect on blood pressure. The NTX resulted in 1.6-fold elevation in plasma total cholesterol and 40% reduction in high density-to-low density lipoprotein ratio (HDL/LDL). However, the lipid profile in NTX rats on the high-calcium diet did not differ from sham-operated controls. The endothelium-mediated relaxations induced by acetylcholine were impaired in NTX rats, whereas the response was normalized by a high-calcium diet. No differences in vasorelaxations by the endothelium-independent vasodilator nitroprusside were detected. In conclusion, improved vasorelaxation after a high-calcium diet could be due to reduced plasma total cholesterol and ameliorated HDL/LDL ratio, although decreased plasma phosphate and parathyroid hormone may also play a significant role in the vascular effects of increased calcium intake.

Parathyroid Hormone- and Deoxycorticosterone Acetate-Induced Hypertension in the Rat

1980 ◽  
Vol 58 (5) ◽  
pp. 365-371 ◽  
Author(s):  
A. Berthelot ◽  
A. Gairard
Keyword(s):  
Parathyroid Hormone ◽  
Hormone Secretion ◽  
Sprague Dawley ◽  
Physiological Concentration ◽  
Deoxycorticosterone Acetate ◽  
Calcium Diet ◽  
Arterial Blood ◽  
Sprague Dawley Rats ◽  
High Calcium ◽  
High Calcium Diet

1. Hypertension induced by treatment with deoxycorticosterone acetate and sodium chloride was studied in male Sprague-Dawley rats and related to parathyroid hormone secretion. 2. Lack of parathyroid hormone (due to parathyroidectomy) or decreased parathormone secretion (due to a high-calcium diet) partially inhibited the development of arterial hypertension. 3. In contrast, in thyroparathyroidectomized rats supplemented with thyroxine, the administration of parathyroid hormone rapidly elevated arterial blood pressure. 4. Maintaining a physiological concentration of serum calcium in the absence of parathyroid hormone (by feeding a high-calcium diet to parathyroidectomized rats) was not sufficient to establish mineralocorticoid hypertension. 5. These results show that parathyroid hormone is necessary for the complete development of mineralocorticoid hypertension.

Effect of increasing calcium intake on urinary sodium excretion in normotensive subjects

1986 ◽  
Vol 71 (4) ◽  
pp. 453-456 ◽  
Author(s):  
Francesco P. Cappuccio ◽  
Nirmala D. Markandu ◽  
Gareth W. Beynon ◽  
Angela C. Shore ◽  
Graham A. MacGregor
Keyword(s):  
Calcium Intake ◽  
Urinary Sodium Excretion ◽  
Urinary Sodium ◽  
Potassium Excretion ◽  
Calcium Diet ◽  
Low Calcium Diet ◽  
High Calcium ◽  
High Calcium Diet ◽  
Normotensive Subjects ◽  
Sodium And Potassium

1. Eight normotensive subjects were studied in a randomized crossover trial of a high calcium diet (1800 mg of calcium/day) for a week against a low calcium diet (200 mg of calcium/day) for a further week. 2. The subjects were placed on a diet containing 200 mg of calcium/day throughout the study and the high calcium diet was achieved by supplementing the low calcium diet with calcium glubionate and galactogluconate. Sodium and potassium intake were kept constant throughout the study. 3. Twenty-four hour urinary sodium, potassium, calcium and phosphate were measured daily. 4. In spite of a highly significant increase in calcium excretion from the low to the high calcium diet (P < 0.0001), there was no increase in sodium or change in potassium excretion with the increased calcium intake. A transient but significant fall in urinary sodium excretion was observed up to the fourth day of the high calcium diet (P = 0.021). Twenty-four hour urinary phosphate excretion fell significantly on the high calcium diet (P < 0.0001). Body weight, blood pressure, plasma renin activity, aldosterone, plasma creatinine and serum ionized calcium did not change. 5. These results suggest that a short-term increase in calcium intake in normotensive subjects does not increase urinary sodium and potassium excretion.

scholarly journals Effect of Silicon Supplementation in Diets with Different Calcium Levels on Bone Mineral Metabolism and Bone Status in Growing Female Rats

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1817-1817
Author(s):  
Mi-Hyun Kim ◽  
Mi-Kyeong Choi
Keyword(s):  
Bone Mineral ◽  
Calcium Intake ◽  
Mineral Metabolism ◽  
Diet Group ◽  
Female Rats ◽  
Bone Mineral Metabolism ◽  
Calcium Diet ◽  
Low Calcium Diet ◽  
High Calcium ◽  
High Calcium Diet

Abstract Objectives Silicon is important for the growth and development of bone and connective tissues. However, few studies have investigated effects of silicon supplementation on bone metabolism on growing females. We evaluated the effect of silicon supplementation on bone mineral metabolism and bone status in growing female rats fed diet with different calcium levels. Methods Sixty 6-wk-old Sprague-Dawley female rats were divided into 6 groups and fed diet with different levels of calcium (0.1%, 0.5%, 1.5%) and silicon (5 ppm, 500 ppm) for 10 weeks. We used a two-way ANOVA test to examine the difference and a significant level was set at P &lt; 0.05. Results Silicon retention significantly increased by silicon supplementation and significantly decreased by high calcium diet (1.5%). Mg retention significantly decreased by high calcium diet. Serum calcium and silicon contents were not significantly different among the 6 groups. Low calcium diet (0.1% calcium) significantly increased serum osteocalcin and C-telopeptide cross-links of type I collagen (CTX) levels, and silicon supplementation significantly decreased CTX levels in the low calcium diet group. Bone mineral density was significantly increased along with greater calcium level in the diet, but was decreased by silicon supplementation in the high calcium diet. Rats in the 0.5% calcium diet group had significant increase in strength of the tibia by silicon supplementation. Conclusions According to our findings, the effect of silicon supplementation on bone metabolism may differ according to the calcium intake levels in growing females. Although further research is needed, when supplementing silicon to improve bone health in growing females, the calcium intake level should be considered. Funding Sources Korea Research Foundation.

scholarly journals High calcium diet down-regulates kidney angiotensin-converting enzyme in experimental renal failure

2004 ◽  
Vol 66 (6) ◽  
pp. 2155-2166 ◽  
Author(s):  
Ilkka Pörsti ◽  
Meng Fan ◽  
Peeter Kööbi ◽  
Pasi Jolma ◽  
Jarkko Kalliovalkama ◽  
...  
Keyword(s):  
Renal Failure ◽  
Angiotensin Converting Enzyme ◽  
Converting Enzyme ◽  
Calcium Diet ◽  
High Calcium ◽  
High Calcium Diet ◽  
Experimental Renal Failure
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