Total body potassium, skeletal muscle potassium and magnesium in patients with Bartter's syndrome

In 20 patients with Bartter's syndrome, who had a serum potassium concentration of 2.75 +/- 0.29 mmol/l (mean +/- SD), the total body potassium (TBK) was measured and compared with a predicted value obtained from regression equations based on age, sex, body height and weight. A significant difference was found between the observed and predicted TBK (mean -320 +/- 306 mmol, p less than 0.01). A positive correlation existed between the serum potassium concentration and the ratio observed TBK/predicted TBK. However, the average fractional reduction in TBK (-11%) was less than the average fractional decrease in serum potassium concentration (-32%). Muscle biopsy specimens were obtained from four patients with Bartter's syndrome and 10 control subjects for analyses of potassium and magnesium. The serum concentrations of potassium and magnesium were decreased in these patients. The potassium content in muscle tissue was lower in two of four patients, but no difference in the amount of magnesium was observed.     

A simple and rapid method for the determination of the concentrations of magnesium, sodium, potassium and sodium, potassium pumps in human skeletal muscle

1. For the diagnosis of electrolyte disorders, data on skeletal muscle composition are often valuable, but rarely available. We have therefore developed a simple and rapid needle biopsy procedure for the determination of the concentrations of K+, Na+, Mg2+ and Na+, K+-pumps in muscle. 2. Using a Bergstr?m needle, biopsies weighing around 25 mg were taken from the vastus lateralis muscle of 18 normal subjects (aged 44-86 years) and extracted with trichloroacetic acid (TCA). The concentrations of K+, Na+ and Mg2+ were 90.7 +/- 1.8, 31.9 +/- 1.6 and 9.5 +/- 0.2 mumol/g wet wt., respectively (means +/- SE). 3. The TCA extraction gave the same values as digestion with 65% HNO3 or 35% H2O2, could be used over the weight range 10-55 mg and showed a Mg2+ recovery of 101.7%. 4. The concentration of Na+, K+-pumps was quantified as the total capacity for [3H]ouabain binding. In vastus lateralis biopsies obtained from six normal subjects the mean value was 258 +/- 16 pmol/g wet wt. 5. Comparison of the concentrations of K+, Mg2+ and [3H]ouabain-binding sites in samples obtained post mortem showed modest variation among different muscles with varying fibre composition. 6. Measurements of the concentrations of K+, Na+, Mg2+ and Na+, K+-pumps in duplicate biopsies of the vastus lateralis yield values which seen representative for the total pool of skeletal muscle fibres and can be performed within a few hours.(ABSTRACT TRUNCATED AT 250 WORDS)     

Reference values of magnesium and potassium in mononuclear cells and erythrocytes of children

Reference values for magnesium and potassium contents of mononuclear cells and erythrocytes were estimated in cord blood and in children from infancy through adolescence. No differences were detected between results for boys and girls. The mononuclear magnesium content was independent of age and was within the adult range of values. No significant correlation was shown between magnesium in serum and in mononuclear cells. Mononuclear potassium also showed no age-related differences. The correlation between magnesium and potassium contents in mononuclear cells was significant: however, the correlation was lower when the magnesium and potassium contents were expressed in terms of protein potent: micromoles or millimoles per gram of protein, respectively. The concentration of magnesium in erythrocytes was significantly lower in cord blood and during the first month of life, compared with that at older ages, and showed no significant correlation with serum magnesium. The concentration of erythrocyte potassium was independent of age and showed a low but significant correlation with erythrocyte magnesium content.     

Correlation between concentrations of magnesium, zinc, and potassium in plasma, erythrocytes and muscles

In 93 patients, consecutively subjected to laparotomy, we studied the correlation between concentrations of magnesium, zinc and potassium in plasma, erythrocytes and muscle tissue. Sixteen percent had hypomagnesemia, 27% hypozincemia, and 53% hypokalemia. There was no difference with regard to the concentration of magnesium and zinc in erythrocytes or in muscle tissue between patients with low and patients with normal/high plasma concentrations of these minerals. Potassium concentration per liter erythrocytes was slightly but significantly higher in patients with hypokalemia than in patients with normal plasma potassium. When expressed per mmol haemoglobin there was, however, no difference in erythrocyte potassium between these two groups. Neither did they differ with regard to potassium concentration in muscles. There was a highly significant correlation between the concentrations of magnesium, zinc and potassium in erythrocytes as well as in muscle tissue, and a significant correlation between magnesium and potassium in plasma. However, no correlation was found between the mineral concentrations in plasma, erythrocytes and muscles, neither for magnesium, nor for zinc or potassium. We therefore conclude that a valid test to estimate total body stores of these minerals cannot be based on analysis of erythrocytes.     

骨骼肌卫星细胞生长因子与运动训练的关系

背景:大运动量训练可以导致骨骼肌组织微细结构的损伤性变化,而骨骼肌卫星细胞的激活、增殖与分化和肌肉组织损伤的修复有密切关系.目的:文章从训练导致肌肉组织结构性损伤需要修复的客观实际出发,提出运动后骨骼肌结构的修复与骨骼肌卫星细胞生长因子之间存在某种依赖关系.方法:由第一作者通过计算机网络检索中国期刊全文数据库(CNKI)和Medline数据库(2000/2010),检索词分别为"骨骼肌卫星细胞,生长因子,运动训练,骨骼肌超微结构"和"Skeletal muscle satellite cells,exercise,growth factor".共检索到97篇文章,按纳入和排除标准对文献进行筛选,共纳入23篇文章.从运动后骨骼肌组织修复与骨骼肌卫星细胞生长因子的激活作用机制进行总结,对两者间的联系进行分析.结果与结论:大强度训练可以导致骨骼肌组织的损伤,而卫星细胞是运动后恢复期骨骼肌修复的关键,其生长因子也与训练方式等因素有关.目前在骨骼肌卫星细胞的生长因子与运动训练之间的联系还缺乏足够的认识与研究.     

骨骼肌卫星细胞生长因子与运动训练的关系

背景：大运动量训练可以导致骨骼肌组织微细结构的损伤性变化,而骨骼肌卫星细胞的激活、增殖与分化和肌肉组织损伤的修复有密切关系。目的：文章从训练导致肌肉组织结构性损伤需要修复的客观实际出发,提出运动后骨骼肌结构的修复与骨骼肌卫星细胞生长因子之间存在某种依赖关系。方法：由第一作者通过计算机网络检索中国期刊全文数据库（CNKI）和Medline数据库（2000/2010）,检索词分别为＂骨骼肌卫星细胞,生长因子,运动训练,骨骼肌超微结构＂和＂Skeletal muscle satellite cells,exercise,growth factor＂。共检索到97篇文章,按纳入和排除标准对文献进行筛选,共纳入23篇文章。从运动后骨骼肌组织修复与骨骼肌卫星细胞生长因子的激活作用机制进行总结,对两者间的联系进行分析。结果与结论：大强度训练可以导致骨骼肌组织的损伤,而卫星细胞是运动后恢复期骨骼肌修复的关键,其生长因子也与训练方式等因素有关。目前在骨骼肌卫星细胞的生长因子与运动训练之间的联系还缺乏足够的认识与研究。     

Can the magnesium content of mononuclear blood cells be altered by oral magnesium supplementation?

A randomized, double-blind, placebo-controlled trial was performed on a rigorously defined group of normal subjects to see if magnesium (Mg) supplementation could affect serum Mg levels or Mg content of mononuclear blood cells. Forty-nine subjects were randomized to either placebo, tablets containing 90% United States recommended daily allowance (USRDA) of Mg, or tablets containing 180% USRDA of Mg. We were unable to demonstrate a statistically significant increase in Mg content of mononuclear blood cells.     

Intracellular magnesium of mononuclear cells from venous blood of clinically healthy subjects

Measurement of intracellular magnesium (Mg2+) may have advantages over serum Mg2+ measurements in the assessment of Mg2+ homeostasis in patients. An accurate and reproducible method of measuring the Mg2+ content of mononuclear cells (lymphocytes and monocytes) from the venous blood of human subjects utilizing commonly available reagents and equipment is described. A well-defined clinical population of 88 subjects (48 males and 40 females) was used as the normal population. The mean mononuclear cell Mg2+ content was 67.8 +/- 13.8 (SD) fg/cell giving a 95% confidence interval normal range of 40-95 fg/cell which compared favorably to the empirical 95% limits of 44-94 fg/cell. The serum Mg2+ measured at the same time was 0.90 +/- 0.06 (SD) mmol/l. No significant correlation was found when comparing serum and mononuclear cell Mg2+ concentrations. Additionally, no significant differences were found when serum and intracellular Mg2+ were analyzed for sex and age with the exception that intracellular Mg2+ tended to be slightly higher in the younger age groups. The routine performance of this assay may require as little as 7 ml of venous blood and was done with a coefficient of variation of 3.0-3.6%.     

Beta-endorphin concentrations in the peripheral blood mononuclear cells of migraine and tension-type headache patients

Levels of beta-endorphin in peripheral blood mononuclear cells have been studied as a new approach to investigating opioid tone in migraine and tension-type headache. Sixty-one patients with migraine without aura, 39 with migraine with aura and 23 with episodic tension-type headache were compared with 37 healthy controls. Peripheral blood samples were taken from patients not enduring headache attacks and not undergoing prophylactic treatment. A significant reduction in peripheral blood mononuclear cell beta-endorphin concentrations was observed in migraine patients with and without aura, but not in tension-type headache patients. Altered transmitter modulation to peripheral blood mononuclear cells may be the cause of this alteration, which could be part of a more diffuse opioid system derangement in migraine subjects.     

Relationship of potassium and magnesium concentrations in serum to cardiac arrhythmias

Low concentrations of potassium and magnesium in serum have been implicated in cardiac arrhythmias; the importance of mild hypokalemia or hypomagnesemia is uncertain. To investigate possible associations among use of diuretics, the concentration of these ions in serum, and the onset of clinically important arrhythmias, we reviewed records of 103 patients admitted to our Coronary Care Unit during three months and found mild to moderate hypokalemia and hypo- magnesemia in 18 and 24%, respectively. The significant correlation between the concentrations of magnesium and potassium in serum at admission (r = 0.27, p less than 0.007) remained constant in patients, whether they were receiving diuretics or not. Potassium concentrations were significantly lower (p less than 0.05) in patients receiving diuretics (3.93 mmol/L) than in those who were not (4.21 mmol/L), but the mean concentrations of magnesium did not differ significantly. Except for myocardial infarction, no single variable or combination of variables was highly predictive of cardiac arrhythmias in these patients. We conclude that there is no strong predictive relationship between mildly decreased concentrations of magnesium or potassium in serum and onset of cardiac arrhythmias.     

线粒体功能与骨骼肌缺血再灌注损伤的关系

目的:观察骨骼肌缺血再灌注后呼吸链电子漏、呼吸控制率、丙二醛和髓过氧化物酶的变化,评价3-硝基-N-甲基水杨酰胺(3-nitro-N-methysolicylamide,NSMA对肢体缺血再灌注损伤的影响。)方法:实验于1998-10/2000-05在解放军第三0四医院创伤外科研究室完成,制备缺血再灌注模型。将35只健康Wistar大白鼠,饲养环境清洁,合格证号军医动字第B98008号。随机分为7组(对照组、缺血2h、缺血2h再灌注1h、缺血2h用NSMA再灌注1h、缺血6h、缺血6h灌注1h、缺血6h用NSMA再灌注1h),选取不同时点骨骼肌标本,提取骨骼肌线粒体、测定线粒体呼吸控制率、抗氰呼吸、经皮测量动脉氧分压及局部相对血流量、测定骨骼肌丙二醛含量和髓过氧化物酶活性、对骨骼肌线粒体超微结构进行透射电镜检测。结果:缺血2h(1.45±0.10)、缺血2h再灌注1h(1.49±0.13)、缺血6h(0.79±0.08)、缺血6h灌注1h(1.32±0.07)RCR比对照组(2.82±0.25)、缺血2h用NSMA再灌注1h(2.93±0.47)、缺血6h用NSMA再灌注1h(2.19±0.38)显著下降(P<0.01);缺血2h用NSMA再灌注1h组线粒体氧化磷酸化偶联程度与对照组相似,缺血6h用NSMA再灌注1h组与相应的缺血2h、缺血2h再灌注1h、缺血6h、缺血6h灌注1h组明显提高;缺血2h(3.02±0.24)、缺血2h再灌注1h(3.30±0.08)、缺血6h(3.36     

A method for the determination of sodium, potassium, magnesium and lithium concentrations in erythrocytes

A technique for the rapid and accurate estimation of intra-erythrocyte concentrations of Na, K, Li and Mg is described. CoEDTA is used as a marker to estimate plasma trapped in the red cell column ; the use of this compound constitutes a novel departure from other marker substances previously used. Plasma trapping was found to average close to 3% (v/v) of the packed cell column. RBC electrolyte values obtained from healthy control subjects were shown to be in good agreement with values reported in the literature.     

Measure of expression of mitochondrial related genes in human mononuclear blood cells,adipose white tissue and smooth muscle cells

BackgroundThe role of mitochondrial dysfunction is currently studied intensively, but the cumbersome procedure of obtaining tissue from humans has restricted the number of subjects studied. Therefore, the aim of the present study was to examine the expression of mitochondrial related genes in blood cells from humans and to compare the results with measurements of mitochondrial membrane potential known to be regulated by thyroid hormones.MethodsIn a group of 17 healthy women subscribed for hysterectomy on a benign basis, muscle tissue, fat tissue samples and blood specimens were obtained.Mitochondrial mass and membrane potential was examined in peripheral blood monocytes by flow cytometry. Gene expression of PGC-1α, PGC-1β, NFR-1, NRF-2 and TFAM was determined by real-time PCR.ResultsAll genes were expressed in the 3 tissues examined, though with different magnitude. Most genes were expressed in mononuclear blood cells at a magnitude comparable to that in white adipose tissue. Furthermore, a significant correlation was observed between PGC-1β and Mitochondrial Membrane Potential (MMP) and Mitochondrial Mass (MM).ConclusionMeasurement of expression of mitochondrial related genes in human mononuclear blood cells may be useful for examining mitochondrial function and regulation by thyroid hormones in humans.