The low calcium content of cellular systems adapted to flow

1974 ◽  
Vol 30 (5) ◽  
pp. 476-477 ◽  
Author(s):  
L. K. Wiersum
2015 ◽  
Vol 44 ◽  
pp. 15-20 ◽  
Author(s):  
P. Burns ◽  
A. Binetti ◽  
P. Torti ◽  
U. Kulozik ◽  
L. Forzani ◽  
...  

1975 ◽  
Vol 49 (5) ◽  
pp. 481-484
Author(s):  
M. Kaye

1. The direct effect of calcium on the hyperparathyroidism of chronic renal failure was studied in rats with induced chronic renal failure, who were fed on a diet low in phosphate and who received supplemental phosphate by injection. They were given a normal (0·8%), or low (0·1%) or high (1·7%) calcium diet. 2. The animals on the low calcium diet had larger parathyroids and more severe bone disease at the end of 4 weeks, indicating the importance of calcium intake in directly influencing the degree of hyperparathyroidism. 3. Increasing the calcium content of the diet from 0·8% to 1·7% produced no additional benefits.


1996 ◽  
Vol 270 (1) ◽  
pp. R11-R21 ◽  
Author(s):  
M. G. Tordoff

Five studies were conducted to characterize the effects on NaCl intake of the interaction between adrenalectomy (ADX) and dietary calcium. Intact rats fed low-calcium diets (0 or 25 mmol Ca2+/kg diet) approximately quadrupled intake of 300 or 500 mM NaCl solution relative to intact rats fed diets with moderate or high calcium content (125, 150, or 500 mmol Ca2+/kg diet) ADX approximately doubled NaCl intake of rats fed moderate or high-calcium diets but decreased NaCl intake of rats fed low-calcium diets to levels similar to those of ADX rats fed moderate of high-calcium diets. Aldosterone replacement (2.4 micrograms/day sc) reduced NaCl intake of ADX rats fed control diets to below levels of intact controls, but the same treatment to ADX rats fed low-calcium diet had no effect on NaCl intake. The reduction in NaCl intake produced by ADX in rats fed low-calcium diet could not be attributed to general debilitation, damage to the adrenal medulla, or altered metabolism of sodium or calcium (i.e., plasma concentration, bone content, or balance). It is proposed that an adrenocortical hormone other than aldosterone mediates the high salt intake of the calcium-deprived rat, and thus the adrenal has both inhibitory and excitatory actions on NaCl intake.


1974 ◽  
Vol 52 (5) ◽  
pp. 972-977
Author(s):  
Claude L. Morin ◽  
Jean Léveillé ◽  
Victor Ling

Generalized hyperaminoaciduria and hyperphosphaturia are associated with human vitamin D deficiency rickets and the effect has been reproduced in animals. The basis for the renal transport impairment was attributed to secondary hyperparathyroidism resulting from hypocalcemia.In this study we attempted over a 16-week period to induce hyperaminoaciduria in Holtzman rats with vitamin D deficient diets of varying calcium content (0.4% and 0.04%) so as to investigate the possibility of a concomitant defect in intestinal transport of amino acids. Despite signs of secondary hyperparathyroidism, generalized hyperaminoaciduria was not in evidence in any of the groups. However, increased urinary excretion of lysine and taurine was demonstrated in rats fed a low calcium diet without vitamin D (LCa−D). The same observation was also made for taurine in rats deprived of vitamin D and on a normal calcium diet (NCa−D) and in animals fed a low calcium diet with vitamin D (LCa+D). The results failed to show any effect of vitamin D deficiency, hypocalcemia, or secondary hyperparathyroidism on the intestinal transport of lysine, alanine, and cycloleucine.


Nature ◽  
1978 ◽  
Vol 273 (5661) ◽  
pp. 377-378 ◽  
Author(s):  
S. K. BOSHER ◽  
R. L. WARREN

1966 ◽  
Vol 17 (6) ◽  
pp. 863 ◽  
Author(s):  
CR Millikan ◽  
BC Hanger

Brussels sprouts, cv. Long Island, grown in sand cultures supplied with either normal or low-calcium nutrient solutions, were used to study the relationship between internal browning of sprouts and the calcium regime of the plants. The interaction of ammonium, magnesium, and potassium ions with calcium nutrition, and the susceptibility of four locally selected strains of Brussels sprouts to the disorder, were also investigated. No symptoms, in either the sprouts or the growing points, were found in plants grown under normal calcium nutrition, but each of the low-calcium treatments, irrespective of other cations, induced a significant amount of internal browning in sprouts. The incidence was greatest in the low-calcium high-magnesium, and least in the low-calcium high-ammonium treatments. Calcium deficiency symptoms of the growing points were most severe in the low-calcium high-magnesium treatment, and only this treatment significantly reduced plant yield. Internal browning occurred in the four strains when grown under the low-calcium high-magnesium treatment. Two strains (Bepi and original early) were more severely affected and developed symptoms earlier than the other two (Sartori and mid-season). However, the Sartori strain was the only one in which low calcium nutrition reduced yield. The calcium content in the sprouts decreased from the wrapper to the meristematic region. In leaves, the calcium content was highest in the leaf margin in all strains except mid-season. Low calcium nutrition greatly reduced the calcium content in sprouts and leaves.


1975 ◽  
Vol 67 (1) ◽  
pp. 105-112 ◽  
Author(s):  
J. P. ASHBY ◽  
F. W. HEATON

SUMMARY The influence of magnesium deficiency on cyclic AMP metabolism was investigated in rats on diets of normal and low calcium content. Magnesium deficiency itself did not significantly affect either the basal concentration or the parathyroid hormone-stimulated formation of cyclic AMP in the renal cortex. Magnesium-deficient rats with hypercalcaemia excreted more cyclic AMP in the urine, but similar rats that developed hypocalcaemia on low calcium intake excreted less than their respective controls. The former type of animals also tended to accumulate more cyclic AMP in the renal cortex in response to the injection of a standard dose of parathyroid hormone, whereas rats of the latter type accumulated less. The activity of parathyroid hormone-stimulated renal cortical adenylate cyclase in vitro was increased by magnesium and reduced by calcium under most conditions, but with low concentrations of magnesium small amounts of calcium had a stimulatory effect. These observations suggest that cyclic AMP metabolism is influenced by metabolic disorders developing secondary to magnesium deficiency.


1968 ◽  
Vol 15 (4) ◽  
pp. 439-455 ◽  
Author(s):  
HIROKO KIYAMA ◽  
SHIZUE TOTSUKA ◽  
FUJIO YOSHIMURA

1993 ◽  
Vol 76 (4) ◽  
pp. 1031-1039 ◽  
Author(s):  
Keizou Tsukamoto ◽  
Hiromasa Shimojima ◽  
Mamoru Ishii ◽  
Naoya Enomoto ◽  
Chitake Yamagishi

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