Magnesium In Blood Plasma Research Articles

Optimization of hypomagnesemia diagnostics as an integral element in paroxysmal atrial fibrillation management strategy

Purpose. To study magnesium status of patients having paroxysmal atrial fibrillation (AF) based on the use of an integrated clinical and laboratory approach. Methods. A prospective cohort study included 58 patients of the cardiology department of New Hospital Medical Association. The main group consisted of 32 patients having frequently recurring paroxysmal AF, the control group consisted of 26 patients without paroxysmal rhythm disturbance. The clinical status, Holter ECG monitoring data, the test results for magnesium deficiency (MD) clinical evidence, laboratory evidence of calcium, magnesium in blood plasma and formed elements, magnesium in whole blood, free fatty acids (FFA) and osmolality in blood plasma were assessed. Results. The score obtained when assessing MD clinical evidence was significantly higher in the main group patients compared with the control group (16.5 (11÷21) vs. 13 (8÷15), p<0.001). A statistically significant magnesium decrease in whole blood was revealed in patients having paroxysmal AF (0.54 (0.46÷0.60) vs. 0.61 (0.59÷0.64), p<0.001) and inside formed elements (0.68 (0.53÷1.07) vs. 1.31 (1.07÷1.44), p<0.001), which reflected changes in their magnesium status to a greater extent than the measured plasma cation concentrations. A close correlation between magnesium content in formed elements (intracellularly) and AF paroxysms frequency (Spearman’s rank correlation -0.51, p<0.001) was established. A violation of calcium to magnesium ratio in blood plasma (2.6 (2.5÷2.9) vs. 3.0 (2.8÷3.1), p=0.004) and intracellularly (4.85 (2.62÷9.3) vs. 1.85 (1.57÷2.07), p<0.001) was revealed in patients having AF. It has been shown that complex forming interactions with free fatty acids may affect intracellular calcium and magnesium content.

Clinical and methodological aspects in the diagnosis of magnesium deficiency in patients with paroxysmal atrial fibrillation

Aim. To determine magnesium deficiency in patients with paroxysmal atrial fibrillation using a comprehensive clinical and laboratory approach. Methods. The prospective cohort study included 35 patients of the cardiology department of the Medical association «Novaya bolnitsa». The main group consisted of 22 patients with frequently recurrent paroxysmal atrial fibrillation, the control group - 13 patients without cardiac arrhythmias. The clinical status, Holter-monitoring of the electrocardiogram, the results of the clinical test for magnesium deficiency, laboratory parameters of calcium, magnesium in blood plasma and formed elements, magnesium in whole blood, free fatty acids and plasma osmolarity were evaluated. Results. The clinical score of magnesium deficiency was significantly higher in patients from the main group compared to the control [16.5 (11÷21) vs 13 (8÷15), p <0.001]. In the main group, there was a decrease of magnesium in the whole blood [0.55 (0.5÷0.59) vs 0.61 (0.58÷0.54), p=0.002] and inside the blood cells [0.68 (0.53÷1.29) vs 1.38 (1.29÷1.44), p <0.001]. In patients with atrial fibrillation there is a shift of the ratio of calcium to magnesium in blood plasma [2.5 (2.5÷3) vs 2.9 (2.8÷3.15), p=0.029] and intracellularly [4.85 (2.62÷9.3) vs 1.7 (1.4÷1.95), p=0.002]. The redistribution of calcium and magnesium is influenced not only by the initial concentration of cations, but also by free fatty acids. The best redistribution was obtained when the concentration of free fatty acids was 900 µmol/l, magnesium 1 mmol/l, and calcium 3 mmol/l, which is consistent with the optimal value of cations in the blood plasma. Conclusion. Patients with paroxysmal atrial fibrillation had a significantly lower magnesium content in whole blood and inside the blood cells; magnesium concentration in the cells and in whole blood closely correlated with the results of the clinical test for evaluating magnesium deficiency; intracellular magnesium content can be influenced by the complexing interaction with free fatty acids.

Colorimetric Determination of Magnesium in Blood and Saliva in Oral Squamous Cell Carcinoma and Potentially Malignant Disorders by Titan Yellow Method

Background: The purpose of this study to evaluate and compare the magnesium concentration in blood plasma and saliva of oral squamous cell carcinoma, potentially malignant disorders and health subjects to serve as a positive marker or indicator in the process of carcinogenesis. Materials and methods: The study consisted of 30 cases each of oral squamous cell carcinoma, potentially malignant disorders and healthy subjects of age and sex matched. The estimation of magnesium in blood plasma and saliva was carried out by colorimeter by using titan yellow method. Results: There was significantly low concentration of magnesium in blood plasma of oral squamous cell carcinoma was noted as compared to potentially malignant disorders (p = 0.000) and healthy subjects (p = 0.000). However, there was no significant difference in magnesium concentration between potentially malignant disorders and healthy subjects. Conclusion: The magnesium concentration was low in both blood plasma and saliva of oral squamous cell carcinoma as compared to potentially malignant disorders and healthy subjects. Thus the magnesium concentration in blood plasma and saliva could be considered as tumor marker, playing an important role in carcinogenesis. Future studies should be carried out for further clarification.

Relationship of ejaculate quality and selected biochemical parameters of blood in cockerels of three laying lines

 Ejaculates and blood plasma were sampled from cocks of three laying lines: Barred Plymouth Rock (BPR), Sussex Light (SU), and Rhode Island Red (RIR). Ejaculates and blood plasma were sampled four times during the laying period of hens. The following ejaculate parameters were determined: sperm motility, concentrations of sperm cells, ejaculate volume. Sperm morphology was examined. In the blood samples, concentrations of glucose, cholesterol, creatinine, calcium, phosphorus, and magnesium were analysed. The motility of spermatozoa of the cocks was 47.0% (BPR), 47.7% (RIR), and 48.3% (SU), respectively. The highest volume of ejaculate was found in BPR line (0.66 cm<sup>3</sup>), the lowest one in SU line (0.46 cm<sup>3</sup>, P ≤ 0.01); the highest sperm concentration was in SU line (2.46 × 10<sup>6</sup>/mm<sup>3</sup>), the lowest one in RIR line (1.96 × 10<sup>6</sup>/mm<sup>3</sup>, P ≤ 0.01). The number of morphologically abnormal sperm cells was similar in all lines − 47.0% BPR, 47.7% RIR, and 48.3% SU, respectively. In general, the occurrence of defective spermatozoa was high in all three lines; the most frequent were tail defects (from 20.3 to 29.7%), while sperm cells with developmental anomalies were less frequent (only 0.3 to 0.4%). Calculated phenotypic correlation between sperm motility on the one hand and the occurrence of defective sperm cells on the other was negative (r<sub>p</sub> = −0.28, P ≤ 0.01), as well as the correlation between sperm motility and sperm numbers, and between sperm motility and ejaculate volume (r<sub>p</sub> = −0.28, P ≤ 0.01 and r<sub>p</sub> = −0.31, P ≤ 0.01, respectively). Negative correlations were found between the level of magnesium in blood plasma and numbers of morphologically defective spermatozoa in the ejaculate, defective heads and defective connecting pieces (r<sub>p </sub>= −0.33, P ≤ 0.01; r<sub>p </sub>= −0.23, P ≤ 0.05; and r<sub>p </sub>= −0.26, P ≤ 0.05). Level of magnesium was positively correlated to sperm motility (r<sub>p </sub>= 0.26, P ≤ 0.05). However, positive correlations existed between concentration of glucose in blood plasma of cocks and numbers of morphologically defective spermatozoa in sampled ejaculates (r<sub>p</sub> = 0.27, P ≤ 0.01). Our finding is in accordance with the results found in mammals and other animals, and it shows an important role of magnesium as a key contributor to the quality of ejaculate in aviary species, in our case in laying lines of domestic fowl (Gallus domesticus).  

Effect of gestational age on cord blood plasma copper, zinc, magnesium and albumin.

The transport of essential trace elements from mother to fetus varies throughout gestation, and the role of transport proteins in the neonate and the mother may change during pregnancy. Magnesium, often used as tocolytic agent, may reach the fetus and appear in cord blood at higher than normal concentrations. To determine cord blood plasma zinc, copper and magnesium concentrations, as well as plasma albumin in premature and full-term newborns, and correlate these values with those of maternal blood plasma at birth. Also, to examine whether cord blood plasma concentration of these elements varies with gestational age. The 35 mother-infant pairs included: 11 in the 38-42-week gestational age (GA), 9 in the 34-37-week GA, 11 in the 29-33-week GA group and 4 in the 24-28-week GA. Magnesium for tocolysis was given to five of the mothers in the 29-33-week GA cohort and two of the women giving birth at 24-28-week GA. Trend analysis showed that while cord plasma zinc decreased with GA at birth, the reverse was observed for copper. There were no differences with GA either in maternal plasma zinc or copper. However, maternal ceruloplasmin tended to decrease with GA (P=0.0174). Maternal and cord blood plasma magnesium exhibited a strong correlation (r=0.942, P<0.001), as well as between cord plasma magnesium and zinc (r=0.448, P<0.01). While the vigorous mother-to-fetus uphill zinc transfer is clear throughout the last trimester, copper remains in cord blood plasma at much lower concentrations than in the mother, suggesting that prematurity may place the newborn infant at a greater risk than the term infant to copper deficiency. This situation, together with a reduced synthesis in the fetus of the transport protein ceruloplasmin, creates another potential challenge in the nutritional support of the premature infant.

The effect of selenium supplementation on plasma sulphur, magnesium and selenium profiles of dairy cows

Interaction of Se supplementation with sulphur and magnesium in blood plasma were studied in dairy cows. Cows were divided into three groups: (1) control, no treatment; (2) cows injected intramuscularly 21–10 d prior to parturition with 45 mg Se and 2040 IU of vitamin E; (3) cows intraruminally administered with two 30-g pellets containing 10% elemental Se 2 mo prior to expected calving. There were no significant effects of Se supplementation on the plasma levels of sulphur and magnesium. Key words: Selenium, sulphur, magnesium, blood, cattle

Metal ion-tetracycline interactions in biological fluids. Part 4. Potential influence of ca 2+ and mg 2+ ions on the bioavailability of chlortetracycline and demethylchlortetracycline, as expected from their computer-simulated distributions in blood plasma

Coordination of tetracydines with calcium and magnesium was previously shown to exert a determining effect on the distribution of these antibiotics in blood plasma. In particular, it was clearly established by computer simulation that the free fraction of the drug is quite negligible with respect to its metal-bound fraction. The bioavailabiity of a tetracycline in blood plasma is thus expected to depend directly on the electrical charge of its predominant metal complexes in the biofluid. On account of the metal to ligand ratio corresponding to the usual therapeutic levels, bioavailability is critically sensitive to the property of the antibiotic to give rise to electrically charged binuclear species. The blocking of one of the two potential binding sites of the tetracycline molecule should thus result in a larger percentage of neutral complexes, hence in a better tissue penetration by the drug. The present work is devoted to the investigation of the coordination of 7-chlortetracycline (CTC) and 6-demethyl-7-chlortetracycline (DMC) with calcium and magnesium in blood plasma. The influence of the chloro substituent is discussed with respect to the objective defined above.

Chloride and Phosphate as Impediments to Silica Urinary Calculi in Rats Fed Tetraethylorthosilicate

Rats fed a dextrose-casein type of diet adequate for normal growth and containing 2% of tetraethylorthosilicate (TES) were used to study the effect of NaCl and Na2SO4 drinking waters, and dietary additions of chloride, sulfate and phosphate on formation of silica urinary calculi. In experiment 1, rats fed the basal-TES diet had a 53% incidence of silica urinary calculi. NaCl or Na2SO4 (0.07 N) drinking waters each increased (P < 0.01) water intake and urine volume, whereas only NaCl reduced (P < 0.05) the incidence of silica urinary calculi. The incidence of calculi in the rats treated with NaCl and Na2SO4 was 15 and 55%, respectively. The saline waters had similar effects on urine pH, silica, phosphorus, magnesium and calcium, as well as blood plasma magnesium and calcium. Plasma phosphorus tended to be higher (P = 0.08) in the NaCl-treated rats. In experiment 2, 50% of rats fed the basal-TES diet developed silica urinary calculi. Addition of 0.2 eq/kg diet of chloride, sulfate or phosphate as sodium salts (phosphate was an equal molar mixture of mono- and dibasic sodium phosphates) resulted in a reduction in silica urinary calculi (P < 0.05) by dietary chloride (15% incidence) and phosphate (5% incidence) but not by sulfate (35% incidence). Water intake and urine volumes did not differ, urine calcium was increased (P < 0.05) by sulfate, and urine phosphorus was increased (P < 0.05) by phosphate. Blood plasma concentrations of calcium and magnesium did not differ, but plasma phosphorus was higher for animals fed the additional phosphate (P < 0.1) or chloride (P < 0.05) in the 2% TES diet.

Glucose-Stimulated Insulin Secretion in Rats with Normal Plasma Calcium Levels: Effects of Calcium Deficiency

Weanling Wistar rats were pair-fed for 9 days a control or a calciumdeficient diet. After a 12-hour fast the rats were injected intraperitoneally with glucose (250 mg/100 g body weight), and blood was collected 15, 30 and 60 minutes after the injection. Before injection, calcium (9.7 ± 0.2 mg/100 ml), glucose and insulin plasma levels were identical in the control and deficient animals, although calcium-deficient animals showed a small but significant increase in blood plasma magnesium levels. Blood glucose levels were higher in the calcium-deficient rats than in control rats 15 to 30 minutes after the glucose injection (15.4 ± 1.4 vs. 9.7 ± 0.4 mM, P < 0.01, 30 minutes after). Plasma insulin levels were significantly lower 15 minutes after the glucose injection (24 ± 4 vs. 73 ± 8 µU/ml; P < 0.01). Calcium deficiency is therefore associated with a decreased response to the glucose tolerance test in the absence of any change in the blood plasma calcium levels.calcium deficiency plasma calcium glucose insulin

Blood Plasma Magnesium, Potassium, Glucose, and Immunoreactive Insulin Changes in Cows Moved Abruptly from Barn Feeding to Early Spring Pasture

Cations and immunoreactive insulin in plasma were measured in 35 lactating cows moved abruptly to early spring pasture. After change of cows from grass-clover hay to fescue-bluegrass pasture containing 22 to 31g potassium/kg dry matter, immunoreactive insulin of 5 Holstein cows increased 30% in 5 days and averaged 45% above prepasture concentrations for 40 days. Magnesium averaged 44% below prepasture content of plasma during this period and was correlated negatively with potassium −.17 and immunoreactive insulin −.37. Thirty Hereford cows were changed from corn silage and grass-clover hay to wheat-rye pasture containing 3.06% potassium in the dry matter. Each day on pasture, 10 cows each were fed 2.3kg cornmeal, 10 were given 30g magnesium oxide by capsule, and 10 were given no supplement. After unsupplemented cows were moved to pasture, immunoreactive insulin rose 51% in 8 days and plasma magnesium fell 24%. Both supplements reduced immunoreactive insulin, but magnesium was maintained higher by magnesium oxide than by cornmeal. Injection of two Holstein cows with insulin (2 IU/kg body weight) reduced plasma concentrations of both potassium and magnesium 20% below that of two cows injected with only physiological saline. Whether elevated plasma insulin may accelerate development of hypomagnesemia in cattle on spring pasture with relatively high potassium content has not been established.

The effect of diet and blood-plasma magnesium concentration on the endogenous faecal loss of magnesium in sheep

SummaryTwo experiments are reported in which mature, castrated male sheep were used to study the effect of a change of magnesium status, as induced by a continuous intravenous infusion of magnesium, on the faecal output of magnesium. In the first experiment, three artificial diets differing markedly in fibre content but extremely low in magnesium were used and in the second experiment, natural diets of frozen grass and of hay and ground barley.With the artificial diets, unit change in plasma magnesium concentration gave the same increase in faecal magnesium output with all three diets but on average faecal magnesium output was highest for the diet containing the highest content of fibre and least for the diet containing an intermediate amount of fibre, and the differences, though small, were statistically significant. With the natural diets, there was no significant difference between diets in the increase in faecal magnesium output in response to a change of plasma magnesium concentration but the order of response was much greater than for the artificial diets. It is concluded that absorption of magnesium from the gut is depressed at high plasma magnesium concentrations.

Interference from citrate using the Titan yellow method and two fluorometric methods for magnesium determination in plasma

This study was undertaken to learn whether or not citrate interfered with the determination of magnesium in blood plasma by the Titan yellow method and by two fluorometric methods that employ 8-hydroxyquinoline or 8-hydroxy-5-quinolinesulfonate. A series of determinations of magnesium in human serum was made by these three methods and by atomic absorption spectrophotometry, which served as a reference. The results support the conclusion that the values for magnesium analyzed in citrated plasma by these three methods represent total plasma magnesium minus the interference from citrate.

Electrolytes and water in the brain and cerebrospinal fluid of the foetal sheep and guinea-pig.

1. Samples of cisternal cerebrospinal fluid (c.s.f.) and blood plasma have been obtained nearly simultaneously from foetal sheep of different ages, the foetus having been exteriorized and maintained in a normal state with respect to its blood gases and arterial pH. The brains were removed from these foetuses and also from foetal guinea-pigs after exsanguination.2. A comprehensive study has been made of the concentrations of water, chloride, sodium, potassium, calcium and magnesium in blood plasma, c.s.f. and brain from foetal sheep and in brain from foetal guinea-pigs during development in utero. Maternal arterial blood plasma, cisternal c.s.f. and brain from the sheep and brain from the guinea-pig have been analysed for comparison.3. Concentrations of the ions analysed in foetal blood plasma are similar to those found by others in the sheep and other species. In the case of calcium, the results suggest an active maintenance of the concentration of this ion in foetal plasma by the placenta.4. The chloride concentration in c.s.f. at ages between 65 days and term (147 days) averaged 1.19 times that in foetal plasma, but only 1.08 at 45-50 days; the sodium concentration in c.s.f. was also slightly reduced at this time. The increase in the c.s.f./plasma ratios for chloride and sodium appears to coincide with the first development of the blood-brain and blood-c.s.f. barriers to non-electrolytes.5. Magnesium was at a slightly higher concentration in c.s.f. than in plasma at all foetal ages and did not vary with age. The concentrations of potassium and calcium in c.s.f. were high at early ages and fell to reach adult concentrations after birth: the mechanisms determining the concentrations of the various ions in c.s.f. develop at very different, largely independent, rates.6. The water content of the cerebral hemispheres of the foetal sheep was stable at 90% of the wet weight till 105 days and fell thereafter. The contents of chloride, sodium and potassium followed paraboloid relations with age. Chloride and sodium reached a peak of 62 and 81 m-equiv/kg respectively between 89 and 105 days in the sheep. Potassium was at a minimum of 65 m-equiv/kg at the same time. The content of water and these electrolytes in the cerebral hemispheres of the foetal guinea-pig underwent similar changes, the maxima and minimum occurring as in the sheep at two-thirds of the total length of the pregnancy, namely 65 days in the guinea-pig. At 46 days in the guinea-pig, chloride in brain reached 53 m-equiv/kg, sodium was 68 m-equiv/kg and potassium was 75 m-equiv/kg. In contrast to the sheep, no reversal of the sodium-potassium ratio occurred. These changes in water and electrolytes probably represent a rise, a peak and a decrease in the volume of the extracellular space of cerebral cortex, but changes in the volume occupied by a cell-type, containing much intracellular chloride and sodium, could also contribute to this phenomenon.7. The calcium content in the cerebral hemispheres of the foetal sheep remained at about 3.0 m-equiv/kg throughout pregnancy. Magnesium in the cerebral hemispheres of both the foetal sheep and the guinea-pig showed a trough in concentration during pregnancy which corresponded approximately in position to the minimum in potassium content and the maxima in chloride and sodium contents. Lowest values were 9.6 m-equiv/kg at 105 days in the sheep and 9.5 m-equiv/kg at 51 days in the guinea-pig.

Improved Performance of a Plasma Jet Equipped with an Inexpensive Atomizer

The erratic performance of the plasma jet in the analysis of magnesium in blood plasma was found to arise from the accumulation of residue in the atomization annulus. This problem was circumvented by the use of an inexpensive Zeiss atomizer which was easily dismantled and cleaned. The plasma jet, equipped with this atomizer, was successfully applied to the routine analysis of magnesium in blood plasma. Compared to both medium- and large-bore Beckman atomizers the Zeiss atomizer provided similar sensitivity and greatly improved repeatability. The plasma jet, equipped with a Zeiss atomizer, may be universally applicable to the analysis of many solutions, particularly those containing salts in high concentration.

CLINICAL MANIFESTATIONS OF HIGH AND LOW PLASMA MAGNESIUM

Although a great deal of clinical significance has been attached to variations in blood calcium, variations in blood magnesium have entirely escaped notice. Very little has been known even about what happens when a patient takes an ordinary purgative dose of epsom salt. Matthew Hay1found that one normal man excreted 28 per cent of the ingested magnesium through the kidneys in twenty-four hours, and Yvon2found 21 per cent. Using a new and convenient method for the quantitative determination of magnesium in blood plasma and urine, we3have found that seven normal men excreted from 40 to 44 per cent (average 42.6 per cent) of the magnesium taken in a single ordinary purgative dose of epsom salt within twenty-four hours after ingestion. However, in spite of the large amount of magnesium absorbed, the concentration of magnesium in the blood plasma (normal, from 1.8 to 2.5 mg.