Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “MAGNESIUM”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 289 records · Page 16Linked to original sources
PubMed2000

Magnesium efficacy in magnesium deficient and nondeficient patients with rapid ventricular response atrial fibrillation.

We assessed the effect of magnesium sulphate (MgSO4) on lowering the rate in ventricular atrial fibrillation (AF), and evaluated the effect of this therapy in magnesium (Mg) deficient and nondeficient patients. This experimental clinical study was performed on 34 patients with rapid AF (ventricular rate [VR] > 120/minute) presenting to the emergency department of a tertiary care university hospital. Patients with systolic blood pressure < or = 100 mmHg, Hb level < or = 11.8, saO2 of < or = 96%, BUN > or = 40 or creatine > or = 1.8 were excluded (n = 15). Nineteen patients were given an initial 2 g MgSO4 bolus i.v. and a 1 g/hour continuous infusion over 6 hours. To evaluate the presence of Mg deficiency, urine was collected from the onset of treatment and continued for the next 24 hours, and the excretion rate of administered Mg was calculated. Ventricular rates were obtained at baseline, after MgSO4 bolus, and every 15 minutes for the first hour. The decrease in the VR was statistically significant at 15, 30 and 60 minutes after Mg therapy (p = 0.0025, p < 0.001, p > 0.001). There was no difference in the response to Mg therapy between Mg deficient and nondeficient patients at 15, 30 or 60 minutes after therapy (p = 0.41, p = 0.28, p = 0.08). It is concluded that i.v. MgSO4 has a statistically significant but clinically limited effect on VR and this effect did not differ between patients with and without Mg deficiency.

Adult↗
PubMed2003

Syntheses and structures of magnesium pyridine thiolates--model compounds for magnesium binding in photosystem I.

Novel magnesium pyridine-2-thiolates were prepared by using alkane elimination chemistry. The resulting complexes display a metal coordination environment composed of sulfur/nitrogen bonding from the intramolecularly stabilized mercaptopyridine ligand, in addition to coordination by the oxygen centers from two THF donors. The compounds are well-suited model compounds for the magnesium centers in Photosystem I, in which magnesium, situated in the central chlorophyll ligand, is bound to sulfur from a nearby methionine residue. All compounds were characterized by (1)H, (13)C NMR, and IR spectroscopy, in addition to Xray crystallography.

Journal Article↗
PubMed1979

Effects of cerebral intraventricular magnesium injections and a low magnesium diet on nonspecific excitability level, audiogenic seizure susceptibility and serotonin.

Cerebral intraventricular injections of 17 and 50 microgram magnesium in artificial cerebrospinal fluid progressively depressed the Non-specific Excitability Level of permanently cannulated 150--200 g rats fed a low magnesium diet for 21 days. Compared with control diet, a low Mg diet caused an increase in brain serotonin. Weanling rats fed a low Mg diet for 2 weeks, then injected with 25 microgram Mg via acute cannulations, displayed reduced audiogenic seizure susceptibility compared with sham-injected controls.

Acoustic Stimulation↗
PubMed1998

Daily magnesium supplementation effect on magnesium deficiency in rats during prolonged restriction of motor activity.

The objective of this investigation was to evaluate the effect of magnesium (Mg) supplements in rats during prolonged restriction of motor activity (hypokinesia [HK]) and in the presence of Mg deficiency, which is characterized by increased rather than decreased plasma Mg concentration, as occurs in ambulatory conditions. The studies were performed during 98 days of HK on 100 13-week-old Sprague-Dawlay male rats weighing 360 to 390 g. They were equally divided into four groups: (1) unsupplemented control animals (UCA), (2) unsupplemented hypokinetic animals (UHA), (3) supplemented control animals (SCA), and (4) supplemented hypokinetic animals (SHA). For the simulation of the hypokinetic effect, SHA and UHA were kept for 98 days in small individual wood cages that restricted their movements in all directions without hindering food and water intake. The SCA and SHA took daily with their food an additional 0.35 mg of Mg. Before and during the hypokinetic period of 98 days, Mg in plasma, urine, and feces, balance of Mg, food intake of Mg, and body weight were determined at different intervals. In SHA and UHA, plasma Mg concentration and excretion of Mg in urine and feces increased significantly compared with SCA and UCA. Magnesium balance was negative in UHA and AHA throughout the hypokinetic period. Body weight and a food intake decreased significantly in SHA and UHA when compared with SCA and UCA. Significant losses of Mg in SHA and UHA occurred in the presence of Mg deficiency and suggest that prolonged HK induces another factor that influences Mg metabolism. We conclude that prolonged HK causes significant changes in Mg values of plasma, urine, and feces and a negative Mg balance in rats, despite Mg supplements leading to Mg deficiency.

Animals↗
PubMed1993

Deficiency in serum ionized magnesium but not total magnesium in patients with migraines. Possible role of ICa2+/IMg2+ ratio.

It has been suggested that magnesium (Mg) may play a role in the pathogenesis of headaches. Serum and intracellular measurements of Mg in headache patients have produced inconsistent results. The recent development of an ion-selective electrode for Mg2+ allowed precise measurement of serum ionized magnesium (IMg2+) in patients with various headache syndromes. Low serum IMg2+ and a high ICa2+/IMg2+ ratio were found in 42% of patients having an attack of migraine, but only in 23% of patients with a severe continuous headache. Total serum Mg was normal in both groups of patients. However, in patients with low serum IMg2+ total serum Mg was lower than in patients with normal serum IMg2+. These results are compatible with the serotonin and vascular concepts of migraine pathogenesis. Low IMg2+ and a high ICa2+/IMg2+ would result in cerebral vasospasm and reduced blood flow in the brain. The activity of serotonin receptors can also be affected by changes in IMg2+ levels. The finding of a difference in IMg2+ levels in two different headache types suggests a possible novel classification of headaches and that migraine patients with a low serum IMg2+ or a high ICa2+/IMg2+ ratio may benefit from Mg supplementation.

Calcium↗
PubMed1980

Rise in serum calcium and magnesium concentrations after vitamin D administration in hypocalcaemic hypomagnesaemic magnesium deficiency.

A patient with hypocalcaemia and hypomagnesaemia secondary to small bowel resection and malabsorption was treated with synthetic vitamin D analogue, 1-alpha hydroxy vitamin D3. A prompt rise in serum calcium concentration and some days later a smaller and transient rise in serum magnesium concentration was observed. These changes in extracellular fluid composition presumably resulted from enhanced calcium and magnesium absorption associated with vitamin D activity.

Calcium↗
PubMedDate not supplied

[Magnesium: physiological and clinical relevance. 1: homeostasis and alterations in the metabolism of magnesium].

Magnesium is the second most abundant cation in intracellular fluid and is an essential electrolyte. It has several critically important roles in the body, namely as a cofactor in numerous enzyme systems, and is involved in phosphate transfer, muscle contractility and neuronal transmission. The physiologic role, homeostasis, causes and clinical manifestations of hypo and hypermagnesemia and their therapy are briefly reviewed. Magnesium treatment is emerging as an important adjunct in the management of a few conditions: prevention and control of seizures in eclampsia, cardiovascular diseases, diabetes mellitus, asthma and others.

Homeostasis↗
PubMed1975

[Calcium, magnesium, phosphorus, chloride and glucose in the blood of cattle following intravenous infusion of solutions with various calcium and magnesium concentration aimed at improving the treatment of hypomagnesemia].

Recent findings on changes in the mineral content of tissues in bovine hypocalcaemia and hypomagnesaemia show the necessity of using different mineral solutions for the treatment and prevention of these conditions. Infusion of 2% CaCl2-6H2O with 10% MgCl2-6H2O and 5% glucose one after the other or in combination produced severe functional changes in cardiac activity and respiration. Recommended concentrations for treatment or prophylaxis of hypomagnesaemia were 10 g magnesium chloride and 2 g calcium chloride, or alternatively 12 g magnesium adipate and 5 g calcium gluconate, in 100 ml of distilled water (total dose 500 ml). This was well tolerated and it overcame the mineral deficiency in tissues.

Animals↗
PubMedDate not supplied

Determination of red blood cell intracellular free magnesium by nuclear magnetic resonance as an assessment of magnesium depletion.

Red blood (RBC) ionized magnesium (Mg2+) was determined by nuclear magnetic resonance (NMR) in order to assess the usefulness of this technique as an index of magnesium depletion. Twenty-four normal subjects underwent a 3-week low-Mg diet. The RBC Mg2+ fell from 209 +/- 9.8 microM before diet to 162 +/- 9.3 microM at the end of the 3 weeks (p < 0.001). In patient populations, 22 hypomagnesemic hospitalized patients had a significantly lower RBC Mg than normal (146 +/- 7.1 microM, p < 0.002), and 37 outpatients with diabetes mellitus had a mean RBC Mg2+ of 172 +/- 7.1 microM which was also significantly lower than normal (p < 0.001). These data suggest that determination of RBC Mg2+ may be used to reflect intracellular Mg status.

Diabetes Mellitus↗
PubMed1991

[Photometric method of the detection of magnesium oxide in the working zone air after using magnesium caustic dust].

The contributors proposed a new highly sensitive selective technique of magnesium oxide detection, based on the Congo red and salicylic acid reaction. The minimal detection level is 0.25 mg of magnesium oxide in the analyzed sample volume. The range of measured concentrations varies from 0.01 to 0.4 mcg/ml. The express technique is simple and selective with Ca (II), Fe (III), AI (III).

Air Pollutants, Occupational↗
PubMed1987

Metabolism of magnesium and zinc in patients treated with antiepileptic drugs and with magnesium lactate.

Fourty-nine patients were examined with epileptic seizures and values of serum and erythrocyte magnesium (sMg, RBC Mg) and serum zinc (sZn) were determined. Chronic deficiency in RBC Mg and sZn were confirmed. The percentage of patients with decreased RBC Mg increased with the time of antiepileptic treatment; significant lowering occurs after 5 years of treatment for RBC Mg and within 5 years for sZn. Various antiepileptics and their combinations have different effects on the degree of the lowering. The therapy of magnesium lactate produces significantly higher RBC Mg and sZn. The clinical, electroencephalographical and biochemical findings are improved.

Adult↗
PubMed1997

Mononuclear blood cell magnesium content and serum magnesium concentration in critically ill hypomagnesemic patients after replacement therapy.

Magnesium (Mg) deficiency, commonly diagnosed as hypomagnesemia based upon low serum Mg concentrations, is a frequent electrolyte abnormality in critically ill patients. Intravenous replacement therapy is empiric and serum Mg concentrations have traditionally been used as guidelines for measuring efficacy. Recent studies have shown that the Mg content of mononuclear blood cells (MBCs) may provide a better index for Mg status than serum concentrations. The purpose of this study was to evaluate the effects of intravenous Mg replacement therapy on MBC Mg content and serum Mg concentrations in critically ill hypomagnesemic patients. Adult patients admitted to the trauma intensive-care unit (ICU) with serum Mg concentration < or = 0.6 mmol/L (< or = 1.5 mg/dL) were considered for study entry. Patients with severe renal disease (Scr > 133 mumol/L), pregnancy, or those who were seropositive for HIV were excluded. Ten patients with moderate (> 0.4-0.6 mmol/L [> 1.0-1.5 mg/dL]) and severe (< or = 0.4 mmol/L [< or = 1.0 mg/dL]) hypomagnesemia received 0.5 and 0.75 mmol/kg of intravenous MgSO4, respectively, over 24 h. MBC Mg content and serum concentrations of magnesium, phosphorus, calcium, sodium, potassium, blood urea nitrogen, creatinine, glucose, and albumin were measured at baseline (0 h), end of infusion (24 h), 36 h, and 48 h. Data were analyzed using ANOVA with repeated measures and a P value < 0.05 was considered significant. Serum Mg concentrations increased significantly from baseline to 48 h (0.5 +/- 0.1 to 0.8 +/- 0.2 mmol/L, P < 0.001). MBC Mg content did not change significantly within the study period (2.6 +/- 1.0 to 3.0 +/- 1.3 fmol/cell, P > 0.7). The doses of MgSO4 (0.5-0.75 mmol/kg) used in this study increased serum Mg concentrations, but did not result in a statistically significant change of MBC Mg content in this group of trauma ICU patients.

Accidents, Traffic↗
PubMed2004

Serum ionized magnesium levels and ionized calcium-to-magnesium ratios in adult patients with sickle cell anemia.

Low levels of total magnesium in sickle cell erythrocytes have been linked to increased sickling due to cell dehydration. We tested the null hypothesis that adult sickle cell anemia (SCA) patients have the same serum level of ionized Mg (Mg(2+)) and Ca(2+)/Mg(2+) ratio as healthy African Americans (AA) and healthy Caucasians (CAUC). We measured serum Mg(2+) and ionized calcium (Ca(2+)) with ion-selective electrodes and calculated the serum Ca(2+)/Mg(2+) ratios in patients with SCA and control groups (AA and CAUC). Seventy-four SCA patients and 61 controls were compared. SCA patients had significantly (P < 0.001) lower levels of serum Mg(2+) (0.52 +/- 0.05) compared to healthy AA (0.57 +/- 0.04) and CAUC (0.62 +/- 0.03). Eighty-six percent of the adult SCA patients had serum Mg(2+) levels below the mean for the AA group, and 96% of SCA patients were above the AA group's mean serum Ca(2+)/Mg(2+). Of the SCA patients studied, 25.6% (95% CI, 16.2-37.2%) had serum Mg(2+) levels below the racially adjusted lower limit of normal and 50% (95% CI, 38.1-61.9%) were above the upper limit of serum Ca(2+)/Mg(2+) for AA controls. By measuring serum Mg(2+) and Ca(2+), we were able to define a subset of SCA patients with hypomagnesemia and elevated Ca(2+)/Mg(2+) ratios, who may benefit from magnesium supplementation.

Adult↗
PubMedDate not supplied

Investigation of the reaction of magnesium with p-nitro-o-carboxylazochromotropic acid and the determination of magnesium in plants and in water.

The formation of a novel complex between magnesium and p-nitro-o-carboxylazochromotropic acid (NCBAC) has been observed which is sensitive and selective at pH 10.4 in the presence of ethylenediamine and fluoride. The constants of formation of this complex have been determined by a spectral correction technique, and the complexation reaction has been applied to the spectrophotometric determination of trace magnesium in plants and in water with satisfactory results.

Hydrogen-Ion Concentration↗
PubMed1993

High magnesium concentration inhibits ligand-stimulated calcium influx and hormone secretion in rat pituitary lactotropes with involvement of intracellular free magnesium.

The effects of extracellular magnesium concentration ([Mg2+]ex) on thyrotropin-releasing hormone (TRH)-stimulated intracellular free calcium mobilization and prolactin secretion were investigated concomitantly with measurement of the intracellular free magnesium concentration ([Mg2+]i). TRH-stimulated intracellular free calcium mobilization was significantly inhibited when the medium was replaced by high Mg2+ medium ([Mg2+]ex = 10 mM) in normal Ca2+ medium. The inhibitory effects of high Mg2+ became apparent concomitantly with an increase in [Mg2+]i from 0.7 to 1.3 mM. High Mg2+ significantly inhibited TRH-induced PRL secretion in a dose-dependent manner in normal Ca2+ medium. TRH-stimulated inositol triphosphate (IP3) production was rather augmented by the replacement with high Mg2+ medium. In summary, high Mg2+ inhibits Ca2+ influx stimulated by TRH in the rat pituitary lactotropes, possibly with the involvement of [Mg2+]i increase. These results have general importance in relation to high Mg(2+)-induced suppression of the biological functions of cells.

Animals↗
PubMed1985

Renal function, serum calcium and magnesium during treatment of advanced bladder carcinoma with cis-dichlorodiamineplatinum: impact of tumour site, patient age and magnesium suppletion.

In a group of ten patients, treated with cisplatin for advanced or metastatic urothelial cancer, renal function deteriorated in six. In a group of 28 patients, treated with cisplatin for tumours outside the urinary tract, renal function was impaired in 14 (50%). Renal function deterioration occurred more frequently in later life. Localization of the primary tumour in the urinary tract does not seem to predispose to renal function impairment. In contrast with reports in the literature, there was a significant decrease in serum calcium levels in spite of magnesium suppletion and normal serum magnesium levels. These calcium levels spontaneously returned to normal some months after the last treatment course with cisplatin.

Adult↗
PubMed1984

Direct measurement of intracellular free magnesium in frog skeletal muscle using magnesium-selective microelectrodes.

Mg2+-selective microelectrodes have been used to measure the intracellular free Mg2+ concentration in frog skeletal muscle fibers. Glass capillaries with a tip diameter of less than 0.4 micron were backfilled with the Mg2+ sensor, ETH 1117. In the absence of interfering ions, they gave Nernstian responses between 1 and 10 mM free Mg2+. In the presence of an ionic environment resembling the myoplasm, the microelectrode response was sub Nernstian (18-24 mV) but still useful. The electrodes were calibrated before and after muscle-fiber impalements . In quiescent fibers from sartorius muscle (Rana pipiens), with resting membrane potentials not less than -82 mV, the intracellular free Mg2+ concentration was 3.8 +/- 0.41 (S.E.) mM (n = 58) at 22 degrees C. No significant change in the intracellular free Mg2+ was observed following extensive (approx. 6 h) incubation in Mg2+-free media. Increasing the external concentration of magnesium from 4 to 20 mM (approx. 15 min) produced a slow and small enhancement (1.8 mM) of [Mg2+]i, which was fully reverted when the divalent cation was removed from the bathing solution. No change in ionic magnesium resting concentration was observed when the muscle fibers were treated either with caffeine 3 mM or with Na+-free solutions. In depolarized muscle fibers (-23 +/- 2.7 mV) treated with 100 mM K+, the myoplasmic [Mg2+] was 3.7 +/- 0.45 (S.E.) mM, n = 6, immediately after the spontaneous relaxation of the contracture. Similar determinations in muscle fibers during stimulation at low frequency (5 Hz), and after fatigue development, showed no changes in the concentration of free cytosolic Mg2+. These results point out that [Mg2+]i is not modified under these three different experimental conditions.

Animals↗
PubMed2002

Serum calcium and magnesium concentrations and the use of a calcium-magnesium-borogluconate solution in the treatment of Friesian mares with retained placenta.

The purpose of the present study was to compare serum calcium and magnesium concentrations in mares with or without a retained placenta (RP) and to evaluate treatment of mares with RP with oxytocin versus oxytocin combined with Ca-Mg-borogluconate solution. Blood samples were obtained within 12 h of foaling from Friesian mares with and without an RP (n = 90 and 65, respectively). Serum Ca and Mg concentrations were analyzed by atomic absorption spectrophotometry. In total, we treated 112 cases of RP in 101 Friesian mares by infusion of either oxytocin dissolved in saline solution or oxytocin dissolved in Ca-Mg-borogluconate solution. We defined RP as the failure to expel all or a part of the fetal membranes up to 3 h after delivery of the foal. We defined a positive response to the treatment as the passage of the entire placenta within 2 h after the infusion. Mares with RP had significantly lower serum calcium levels within 12 h of foaling than mares without RP. Serum magnesium levels showed no difference. Sixty-four percent of the mares treated with oxytocin in Ca-Mg-borogluconate solution responded positively to the treatment, compared to 44% of the mares treated with oxytocin in saline solution (P < 0.05).

Animals↗