ABOLITION OF MAGNESIUM-INDUCED HYPOCALCAEMIA BY ACUTE THYRO-PARATHYROIDECTOMY IN THE CAT

1970 ◽  
Vol 64 (1) ◽  
pp. 150-158 ◽  
Author(s):  
S. Pors Nielsen
Keyword(s):  
Sodium Chloride ◽  
Flow Rate ◽  
Magnesium Chloride ◽  
Calcium Concentration ◽  
Plasma Calcium ◽  
Magnesium Concentration ◽  
Isotonic Sodium Chloride ◽  
Plasma Calcium Concentration ◽  
High Concentrations ◽  
Plasma Magnesium

ABSTRACT Intravenous infusion of isotonic magnesium chloride into young cats with a resultant mean plasma magnesium concentration of 7.7 meq./100 g protein was followed by a significant lowering of the plasma calcium concentration in 90 minutes. The rate of decrease of plasma calcium is consistent with the hypothesis that calcitonin is released by magnesium in high concentrations. There was no decrease in the plasma calcium concentration in cats of the same weight thyroparathyroidectomized 60 min before an identical magnesium chloride infusion or an infusion of isotonic sodium chloride at the same flow rate. The hypercalciuric effect of magnesium could not account for the hypocalcaemic effect of magnesium. Plasma magnesium concentration during magnesium infusion into cats with an intact thyroid-parathyroid gland complex was slightly, but not significantly higher than in acutely thyroparathyroidectomized cats.

scholarly journals STANNIECTOMY INCREASES RENAL MAGNESIUM AND CALCIUM EXCRETION IN FRESHWATER NORTH AMERICAN EELS (ANGUILLA ROSTRATA)

1993 ◽  
Vol 181 (1) ◽  
pp. 107-118
Author(s):  
D. G. Butler
Keyword(s):  
North American ◽  
Calcium Concentration ◽  
Urinary Calcium ◽  
Plasma Calcium ◽  
Magnesium Concentration ◽  
Calcium Excretion ◽  
Plasma Calcium Concentration ◽  
Magnesium Excretion ◽  
Plasma Magnesium ◽  
American Eels

The corpuscles of Stannius are linked to the renal transport of magnesium in freshwater North American eels. The urinary magnesium concentration and rate of magnesium excretion increased 3 days after the corpuscles had been removed, a trend which continued throughout a 14 day observation period. There was no overall change in urine flow rates except for a brief 50 % reduction 2 days after stanniectomy. Plasma magnesium concentrations drifted downward after stanniectomy. In contrast, plasma calcium concentrations increased significantly within 2 days following stanniectomy and they continued to increase thereafter. Urinary calcium concentrations and the rate of urinary calcium excretion increased 7 days after stanniectomy, implying that the renal response was subject to the increase in plasma calcium concentration: the urine/plasma calcium ratio remained constant. Even though the urinary calcium concentration increased after stanniectomy, the increase in urinary magnesium concentration was proportionally greater.

scholarly journals Electrolyte and Plasma Changes After Ingestion of Pickle Juice, Water, and a Common Carbohydrate-Electrolyte Solution

2009 ◽  
Vol 44 (5) ◽  
pp. 454-461 ◽  
Author(s):  
Kevin C. Miller ◽  
Gary Mack ◽  
Kenneth L. Knight
Keyword(s):  
Plasma Volume ◽  
Calcium Concentration ◽  
Plasma Osmolality ◽  
Plasma Potassium ◽  
Sodium Concentration ◽  
Magnesium Concentration ◽  
Plasma Sodium ◽  
Plasma Sodium Concentration ◽  
Plasma Calcium Concentration ◽  
Plasma Magnesium

Abstract Context: Health care professionals advocate that athletes who are susceptible to exercise-associated muscle cramps (EAMCs) should moderately increase their fluid and electrolyte intake by drinking sport drinks. Some clinicians have also claimed drinking small volumes of pickle juice effectively relieves acute EAMCs, often alleviating them within 35 seconds. Others fear ingesting pickle juice will enhance dehydration-induced hypertonicity, thereby prolonging dehydration. Objective: To determine if ingesting small quantities of pickle juice, a carbohydrate-electrolyte (CHO-e) drink, or water increases plasma electrolytes or other selected plasma variables. Design: Crossover study. Setting: Exercise physiology laboratory. Patients or Other Participants: Nine euhydrated, healthy men (age  =  25 ± 2 years, height  =  179.4 ± 7.2 cm, mass  =  86.3 ± 15.9 kg) completed the study. Intervention(s): Resting blood samples were collected preingestion (−0.5 minutes); immediately postingestion (0 minutes); and at 1, 5, 10, 15, 20, 25, 30, 45, and 60 minutes postingestion of 1 mL/kg body mass of pickle juice, CHO-e drink, or tap water. Main Outcome Measure(s): Plasma sodium concentration, plasma magnesium concentration, plasma calcium concentration, plasma potassium concentration, plasma osmolality, and changes in plasma volume were analyzed. Urine specific gravity, osmolality, and volume were also measured to characterize hydration status. Results: Mean fluid intake was 86.3 ± 16.7 mL. Plasma sodium concentration, plasma magnesium concentration, plasma calcium concentration, plasma osmolality, and plasma volume did not change during the 60 minutes after ingestion of each fluid (P ≥ .05). Water ingestion slightly decreased plasma potassium concentration at 60 minutes (0.21 ± 0.14 mg/dL [0.21 ± 0.14 mmol/L]; P ≤ .05). Conclusions: At these volumes, ingestion of pickle juice and CHO-e drink did not cause substantial changes in plasma electrolyte concentrations, plasma osmolality, or plasma volume in rested, euhydrated men. Concern that ingesting these volumes of pickle juice might exacerbate an athlete's risk of dehydration-induced hypertonicity may be unwarranted. If EAMCs are caused by large electrolyte loss due to sweating, these volumes of pickle juice or CHO-e drink are unlikely to restore any deficit incurred by exercise.

Plasma Magnesium and Calcium Levels in Depressive Psychosis

1972 ◽  
Vol 120 (559) ◽  
pp. 683-684 ◽  
Author(s):  
G. J. Naylor ◽  
Laura W. Fleming ◽  
W. K. Stewart ◽  
H. B. McNamee ◽  
D. Le Poidevin
Keyword(s):  
Divalent Cation ◽  
Calcium Concentration ◽  
Depressive Illness ◽  
Plasma Calcium ◽  
Ionized Calcium ◽  
Total Plasma ◽  
Total Calcium ◽  
Before And After ◽  
Plasma Calcium Concentration ◽  
Plasma Magnesium

There have been reports of the association of alterations in the divalent cation content of plasma with depressive illness. Coirault and colleagues (1959) found increased ionized calcium levels despite decreased total plasma calcium concentration in patients recovered from depression. More recently, Frizel and colleagues (1969) have reported normal plasma ionized and total calcium levels both before and after recovery from depression.

THE EFFECTS OF HYPERMAGNESAEMIA ON CALCITONIN SECRETION IN VIVO

1971 ◽  
Vol 51 (2) ◽  
pp. 381-386 ◽  
Author(s):  
A. D. CARE ◽  
N. H. BELL ◽  
R. F. L. BATES
Keyword(s):  
Calcium Concentration ◽  
Secretion Rate ◽  
Magnesium Concentration ◽  
Maximum Effect ◽  
Thyroid Glands ◽  
Plasma Calcium Concentration ◽  
Plasma Magnesium ◽  
Normal Calcium

SUMMARY The influence of magnesium on calcitonin (CT) secretion rate has been studied in pigs by perfusion of porcine thyroid glands, isolated in situ, under controlled conditions of flow rate and blood electrolyte composition. At concentrations of 4·4–12·7 mequiv./l, magnesium stimulated CT secretion in the presence of a normal calcium concentration in the perfusate. The maximum effect was reached at a concentration of about 7 mequiv. Mg/l. At higher magnesium concentrations, the secretion rate of CT tended to revert towards that found with concentrations of calcium and magnesium within the normal range. When hypermagnesaemia was superimposed on hypercalcaemia there was a fall in the secretion rate of CT as the Mg: Ca ratio in the perfusing blood plasma approached 1. The stimulatory effect of hypermagnesaemia was usually less than that caused by an equimolar increase in plasma calcium concentration. The results suggest that changes in plasma magnesium concentration probably do not influence CT secretion under normal conditions.

Effect of Small Increments in Plasma Calcium Concentration on the Responsiveness of Forearm Resistance Vessels to Verapamil in Normal Subjects

1984 ◽  
Vol 67 (6) ◽  
pp. 613-618 ◽  
Author(s):  
B. F. Robinson ◽  
R. J. W. Phillips
Keyword(s):  
Calcium Concentration ◽  
Venous Blood ◽  
Normal Subjects ◽  
Plasma Calcium ◽  
Calcium Handling ◽  
Membrane Function ◽  
Resistance Vessels ◽  
Initial Control ◽  
Plasma Calcium Concentration ◽  
Small Increments

1. The effect of a small increase in local plasma calcium concentration on the responsiveness of the forearm resistance vessels to verapamil has been examined in normal subjects, by using a plethysmographic method with infusion of calcium and other agents into the brachial artery. 2. Infusion of calcium at a rate which increased the concentration in forearm venous blood by about 0.5 mmol/l caused basal blood flow to fall by 19% and the dilator response to verapamil to fall by 35% (n = 8; P<0.02). 3. When, after 46 min, the infusion of calcium was discontinued, the dilator response to verapamil increased to reach a level 53% higher than the initial control (n = 8; P<0.02). 4. Infusion of calcium had no effect on the dilator response to sodium nitroprusside. 5. Infusion of noradrenaline at a rate which caused a greater reduction in basal flow than that induced by calcium had no effect on the response to verapamil. 6. It is concluded that the dilator response to verapamil, which is thought to reflect activity of the potential operated system for calcium entry, is selectively depressed by a small elevation of plasma calcium concentration, but subsequently becomes elevated. These findings point to an important role for calcium in the regulation of membrane function in the resistance vessels and support the view that altered calcium handling may contribute to the development of primary hypertension.

Effect of magnesium loading on magnesium delivery to the juxtamedullary end-descending limb

1985 ◽  
Vol 248 (1) ◽  
pp. F145-F151
Author(s):  
D. R. Roy
Keyword(s):  
Flow Rate ◽  
Magnesium Concentration ◽  
Group 4 ◽  
Intravenous Magnesium ◽  
Group 3 ◽  
Group 2 ◽  
Magnesium Excretion ◽  
Plasma Magnesium ◽  
Normal Controls ◽  
Group 1

Previous micropuncture and microperfusion studies in acutely hypermagnesemic rats have yielded conflicting results with respect to magnesium transport in Henle's loop. The following experiments were performed to reexamine, by micropuncture of papillary end-descending limb, whether magnesium undergoes intratubular secretion in magnesium-loaded rats. Group 1 animals served as normal controls; group 2 animals received an acute intravenous magnesium load; group 3 animals were orally magnesium loaded for 3 wk before receiving an acute intravenous magnesium load during micropuncture; group 4 animals were acutely thyroparathyroidectomized and water loaded before receiving an acute magnesium load. Fractional magnesium delivery to the end-descending limb did not differ from the corresponding value observed in the superficial proximal tubule in normal animals (67 +/- 5.3 vs. 76 +/- 7.6%). Acute magnesium loading raised plasma magnesium concentration and fractional magnesium excretion more than twofold but did not change fractional magnesium delivery to the end-descending limb or superficial nephron significantly from control values (75 and 73%). Chronic oral magnesium loading raised daily urinary magnesium excretion threefold (183 vs. 53 mumol X day-1 X 100 g body wt-1, P less than 0.05), but acute magnesium loading in this group did not significantly alter fractional delivery to the end-descending limb (85 +/- 10%, NS). Increasing intratubular flow rate while acutely raising plasma magnesium concentration (group 4) also did not induce intratubular magnesium secretion. The absence of significant changes in fractional magnesium delivery to the end-descending limb during magnesium loading suggests that intratubular magnesium secretion, if at all present, is very small and of questionable significance.

Nature of calcemic effect of 1,25-dihydroxyvitamin D3 in experimental hypoparathyroidism

1983 ◽  
Vol 244 (4) ◽  
pp. E313-E316
Author(s):  
E. Hefti ◽  
U. Trechsel ◽  
H. Fleisch ◽  
J. P. Bonjour
Keyword(s):  
Calcium Concentration ◽  
Calcium Absorption ◽  
Single Injection ◽  
Plasma Calcium ◽  
Constant Infusion ◽  
Feeding Period ◽  
Daily Fluctuation ◽  
Dihydroxyvitamin D3 ◽  
1,25 Dihydroxyvitamin D3 ◽  
Plasma Calcium Concentration

The influence of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] treatment on the daily fluctuation of plasma calcium concentration ( [Ca]P1) in relation to the feeding-fasting alternation has been studied in vitamin D-replete sham-operated (sham) and thyroparathyroidectomized (TPTX) rats fed a normal Ca diet. 1,25(OH)2D3 was given (26 or 39 pmol/day) intraperitoneally either by single injection or constant infusion using osmotic minipumps. After 7 days of treatment [Ca]P1 was measured at 4-h intervals for 24 h. Pair-fed, sham and TPTX animals received the solvent vehicle intraperitoneally. The results show that in sham rats the very moderate daily fluctuation of [Ca]P1 was not accentuated by 1,25(OH)2D3. A marked fluctuation of [Ca]P1 in relation to the food intake was observed in untreated TPTX as compared with sham rats. In TPTX rats 1,25(OH)2D3 increased the fasting [Ca]P1. In contrast the rise in [Ca]P1 during feeding was not significantly accentuated by 1,25(OH)2D3. The daily fluctuation of [Ca]P1 was the same whether the dose of 1,25(OH)2D3 was given in one single injection or by constant infusion, suggesting that this hormone is not involved in the hour-to-hour regulation of [Ca]P1. In conclusion, in the absence of parathyroid glands, 1,25(OH)2D3 given in doses that stimulate intestinal calcium absorption has a much more pronounced effect on the fasting calcemia than on the rise in calcemia observed during the feeding period. These results suggest that the mobilization of calcium from bone could play an important role in the calcemic effect of 1,25(OH)2D3 when given in the hypoparathyroid state.

Cyclosporin-induced hypomagnesaemia and renal magnesium wasting in rats

1988 ◽  
Vol 75 (5) ◽  
pp. 509-514 ◽  
Author(s):  
Norman L. M. Wong ◽  
John H. Dirks
Keyword(s):  
Magnesium Chloride ◽  
Magnesium Concentration ◽  
Group Iii ◽  
Cyclosporin Treatment ◽  
Group I ◽  
Three Phase ◽  
Group Ii ◽  
Renal Magnesium Wasting ◽  
Magnesium Excretion ◽  
Plasma Magnesium

1. Twenty-four hour clearance studies were performed on three groups of rats to determine the hypomagnesaemic effect of cyclosporin. Group I rats served as controls, whereas group II rats received 10 mg of cyclosporin/kg and group III rats received 20 mg of cyclosporin/kg daily. 2. After 7 days of cyclosporin treatment, plasma magnesium concentration was 1.04 ±0.01 mmol/l in control rats compared with 0.85 ±0.01 mmol/l in group II and 0.81 ±0.02 mmol/l in group III. After 14 days of cyclosporin administration, group III rats developed severe hypomagnesaemia (0.67 ± 0.01 mmol/l). This reduction in plasma magnesium was associated with an increase in the urinary excretion of magnesium. 3. This reduction in plasma magnesium and increment in magnesium excretion returned to normal 7 days after cessation of treatment. 4. Additional three-phase acute clearance experiments were performed on eight normal and 12 cyclosporin-treated rats (20 mg/kg). These animals were subjected to acute magnesium chloride infusion. After graded magnesium chloride infusion, despite a similar rise in plasma magnesium, the fractional magnesium excretion was significantly higher in the cyclosporin-treated animals. 5. Analysis of the fractional intestinal absorption of magnesium suggested that the development of hypomagnesaemia after cyclosporin treatment is due to magnesium loss by the kidney. Furthermore, this effect of cyclosporin on magnesium transport is only present during cyclosporin treatment and is reversible when treatment with cyclosporin is withdrawn.

Sign in / Sign up

Export Citation Format

Share Document