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Potassium is a main cation in the intracellular compartment, with nearly 80% of stores being present in muscles, liver, bone and red blood cells. Intracellular potassium concentration is about 140-150 mmol/l in contrast to more than 30 times lower extracellular levels (3.5-5.0 mmol/l).This transmembrane gradient is crucial for maintenance of the membrane resting potential and neuro-muscularfunctioning, including the heart. In this review the physiological regulation of potassium balance is shortly reviewed to set a background for understanding its disorders.

Hyperkalemia is a common and potentially lethal clinical problem. It may be caused by several drugs, especially those which target the renin-angiotensin--aldosterone system, inability of kidney to excrete potassium, a shift of these ions into the extracellular fluid, or a combination of those mechanisms. It can be also spurious, caused by hemolysis after blood drawing. In the article the conditions associated with hyperkalemia, its diagnosis and the management are reviewed.

Unlabelled: A patient of 31 years of age with an atypical overhydrated hereditary stomatocytosis is described. The diagnosis was established on the basis of a markedly increased red cell volume with low MCHC, high osmotic fragility of red cells, but increased binding of eosin-5-maleimide (EMA) to red cells, presence of stomatospherocytes and large spherocytes in blood and a high sodium and low potassium concentration in erythrocytes. A double band 7 was found by SDS-PAGE of the erythrocyte membrane, but even when only one them was taken into account, the level of stomatin was normal. Expression of stomatospherocytes in patient's blood was erratic: in blood films prepared in 2005, both stomatospherocytes and large spherocytes were present but in those from 2008 large erythrocytes of spherocyte morphology predominated. Clinically, the disease symptoms were typical for haemolytic anemia. When heparinized blood of the patient was kept at 0 degrees Celsius for 24 h, the haemolysis of red cells amounted only to 2%. The patient's son, 5 years old, suffers from the same disease., Conclusion: In spite of its rarity, hereditary stomatocytosis and allied disorders should be taken into consideration in differential diagnosis of haemolytic anemia including newborns. The diagnosis is supported by finding increased binding of eosin-5-maleimide (EMA) dye to patients' erythrocytes associated with their elevated osmotic fragility. Absence of a significant count of stomatocytes in the blood does not exclude the diagnosis of overyhydrated hereditary stomatocytosis.

Melatonin occurs naturally in human organism, and its basic and the best investigated function is stabilization of biological rhythms, mainly day-night cycle. Properties very profitable for organisms, this hormone owes to its great ability of free radical scavenging and antioxidant activity. Connection between melatonin and elements occurring in human organism can be based on various relationships. Calcium ions play active role in melatonin biosynthesis, and sodium and potassium ions, thank to their properties of membranes polarization, influence melatonin penetrating possibility into cells, where this active molecule can exerts its physiologic functions. Another type of relationship exists between melatonin and zinc ions. Genomic action of melatonin appears in its ability to stimulate antioxidant genes expression, and its direct cellular action appears in increasing of these enzymes activity, among which very important place takes zinc-enzyme-superoxide dismutase (SOD). Melatonin also prevents poisoning by such elements like chromium (III) and (VI), iron and copper, through levelling toxic actions of these ions on organism. The role of melatonin in these processes relies mainly on scavenging of arisen free radicals, detoxification of hydrogen peroxide and combining excess of toxic ions into compounds harmless for organism.

Three elderly patients with severe symptomatic bradyarrhythmia due to iatrogenic hyperkalemia are presented. In all patients potassium - lowering therapy was effective; two patients required temporary pacing. The issue of iatrogenic hyperkalemia and treatment options are discussed.

In breast cyst fluid obtained from 50 patients age (47.1 +/- 2.3) sodium, potassium, oestrone (E1), oestradiol (E2) androgens, progesterone, (P) and Epidermal Growth Factor--EGF were determined. Markedly higher oestrogens, progesterone, testosterone, and EGF-levels were detected in cyst fluid than in blood. These data have confirmed previous results and have clearly shown that breast cyst fluid with high potassium (ratio K/Na > 1.0) contains more oestrogens, progesterone, testosterone, androstenedione and EGF than the group with low electrolyte ratio. This finding might be put in correlation with the fact that patients with high ratio K/Na may a higher risk of breast cancer than those with low electrolyte ratio.

We have examined the concentration of sodium and potassium in myomas, myometrium and peripheral blood of 55 women and in 69 women calcium was examined. The levels of these elements were correlated to the phase of the menstrual cycle. The sodium concentration is similar in the examined tissues in both phases. The potassium concentration is significantly higher in myomas and myometrium in comparison with the peripheral blood in both phases of the menstrual cycle. The calcium concentration is significantly lower in myomas and myometrium during the proliferation and significantly lower in the myomas comparing to the myometrium and peripheral blood in the secretion. Concerning the differences between two phases of the cycle we observed that the level of the potassium is significantly lower in the myomas in the proliferative phase but the the level of the sodium is higher in the secretory phase.

Aim: The aim of our paper was to observe the physical and chemical changes in the aqueous humor, lens, gelatous and fluid part of the vitreous body after the sulfurhexafluoride injection into the vitreous body., Material and Methods: The New Zealand rabbits were randomized into the control and experimental group which were injected the gas into the vitreous body. The interesting samples were investigated during the 2nd, 7th and 14th day of the experiment. We estimated the volume of the fluid part of the vitreous body, its electrical resistance, the whole protein concentration (in the aqueous humor, lens and vitreous), and electrolite concentration (in the aqueous humor and fluid part of the vitreous body)., Results: We observed the increase of the fluid fraction in the vitreous body with the increasing of the whole protein concentration, changes in the K+ concentration and decrease of the electrical resistance in the vitreous fluid fraction., Conclusion: On the basis of our experimental results we can assume that expanding sulfurhexafluoride gas could mechanically disrupt the vitreous structure. Moreover, the rapid intrabulbar pressure increase after the injection can cause the cilliary body ischaemia and the eye barrier collapse.

The concentrations of Na+, K+, Li+ have been assayed in the epidermis samples from 58 cadavers and 20 healthy individuals. The samples have been taken from the heels, and assayed with 2 flame photometers (Corning 480), using standard solutions supplied by the manufacturer. A concentration of Na+ and K+ in men exceeded the levels of these ions in women by two-fold. A level of Li+ is the same in both sexes and amounts to 2.8 mEq/kg. The Na+:K+ ratio in the epidermis of women and men is about 4:1. In the samples collected from cadavers, the difference in Na+ and K+ levels has been lower but Li+ level has been higher, amounting to 4.3 mEq/kg.

The effect of catecholamines on the regulation of extra-renal potassium homeostasis is well known in some pathological conditions such eg. chronic renal failure. However, the role of catecholamines on potassium homeostasis in acute renal failure has not been established yet. There are only scarce amount literature on this issue showing that both clinical and experimental acute renal failure plasma catecholamines are elevated. Presumably, acute renal failure associated hyperkalemia is ameliorated by raised plasma catecholamine concentration.

Effect was studied of acetate haemodialysis with ultrafiltration (HD) on left ventricular (LV) systolic and diastolic function of 25 uraemic patients (age: 19-49 years, x = 33.6, SD = 8.9) treated by HD. M-Mode, 2D-, and Doppler-echocardiography was performed to determine LV filling pattern, LV end-systolic (LVIDS) and end-diastolic diameter (LVIDD) immediately before and after each hour of HD. Values of LV mass index (LVMI), fractional shortening (FS), ejection fraction (EF) and velocity of circumferential fiber shortening (Vcf) were also assessed. Simultaneously creatinine, magnesium, potassium, natrium and ionized calcium concentrations were measured, together with body weight and blood pressure. Left ventricular dimensions and LVMI were greatly increased in uremic patients as compared to 25 healthy subjects of similar age. HD resulted in a significant (p < 0.005) lowering of creatinine and potassium concentrations, a nonsignificant decrease of sodium and magnesium levels and in a significant (p = 0.05) increase a significant decrease of LVIDD, LVIDS, Ve,Ve/Va (p < 0.05) and a nonsignificant increase of FS, EF and Vcf. An effective volume depletion HD has no significant influence on left ventricular systolic function and a negative influence on its filling pattern.

The study aimed at determining relationship between plasma free fatty acid (FFA) and impaired glucose tolerance in hyperthyroid patients prior to and after the treatment with propranolol or acebutolol, i.e. following lipolytic blockade leading to a decrease in plasma FFA levels. The study included 31 untreated hyperthyroid patients and 12 normal subjects serving as a matched control group. IVGTT was performed in all subjects. Venous blood specimens were collected at 0, 3, 5, 15, 30, 60, and 120 minutes following intravenous glucose load (0.33 g/kg body weight during 3 minutes). Nineteen patients with normal K values were randomized to groups treated either with propranolol in the daily dose of 120 mg (10 patients) or 400 mg acebutolol (9 patients). Twelve patients with low K values were randomized to groups treated with either propranolol (5 patients) or acebutolol (7 patients). The second IVGTT was performed after 7 days of therapy. Glucose, FFA and insulin levels were determined in all blood samples whereas T3 and T4 were determined in samples taken at 0 minute. Plasma T3, T4 and insulin levels were assayed with radioimmunological technique, glucose--with glucose oxidase, and FFA--colorimetrically. Significantly higher plasma FFA levels were found in patients with low K values in comparison with control group. There were no differences in plasma FFA levels in both hyperthyroid patients and normal subjects. Acebutolol but not propranolol normalized K value whereas propranolol (but not acebutolol) significantly decreased acute phase of insulin secretion. Plasma glucose and insulin levels as well as K value were not altered during propranolol acebutolol therapy in patients with normal K value.(ABSTRACT TRUNCATED AT 250 WORDS)

Diminished activities of Na/K/ATPase and Na/K/2Cl-cotransport in arterial smooth muscles lead to vasoconstriction. We found it interesting to check if a decrease in activities of those ion transports are present in other diseases with smooth muscles hyperreactivity; bronchial asthma and COPD. The study was performed on lymphocytes collected from 57 patients with atopic asthma, nonatopic asthma and COPD; the groups consisted of 18, 28 and 11 patients respectively. Control group was composed of 15 healthy subjects. There were no significant differences in Na/K/-ATPase and Na/K/2Cl-cotransport activities either in the exacerbation compared to the remission in the examined group, or in patients versus controls. Na/K-ATPase activity was strongly dependent on pO2.

The present study aims to answer the following questions: 1. do secretion of volume related hormones in patients with EH pre- and post treatment with propranolol differ from normotensive subjects if examined in thermal dehydration conditions; 2. is the electrolyte composition of thermal sweat related to the plasma profile of volume related hormones? and 3. does treatment by propranolol influence sweat electrolytes in EH patients. In 15 patients with EH and in 20 healthy subjects a thermal dehydration test was performed. In patients with EH this test was done twice: before treatment and after 6 weeks of propranolol therapy. In all subjects the plasma renin activity (PRA), aldosterone (Ald), AVP and ANP were measured before and after thermal dehydration. In sweat samples collected after 15' and 45' of thermal dehydration (the concentration of Na, K and Cl was assessed). In hypertensive patients before propranolol treatment significantly higher values of PRA, Ald and ANP were found, while sweat concentrations of Na and Cl were significantly lower than in controls. After propranolol treatment sweat electrolytes concentrations showed a tendency to normalize. No significant correlation was found between the plasma hormonal profile and sweat Na, K and Cl concentrations respectively both in controls and patients with EH pretreatment. A significant positive correlation was noticed only in hypertensive patients posttreatment between ANP and sweat potassium concentration respectively, and significant negative correlation between PRA and sweat sodium and chloride concentration. From results obtained in this paper it seemed, that volume related hormones (Ald, AVP, ANP) do not seem to influence markedly the electrolyte composition of thermal sweat both in healthy subjects and in hypertensive patients.

The aim of the study was to evaluate changes in potassium level at 1 to 4 days in patients with acute myocardial infarction. The studies comprised 103 patients including 85 men and 18 women, aged from 31 to 90 years (mean age 56.7 +/- 11.7). A control group consisted of 51 patients (40 men, 11 women) aged from 34 to 74 years (mean = 56.7 +/- 10.7) on intensive diuretic therapy due to heart failure without myocardial infarction. In order to establish our own normal limits of potassium level in the blood serum and erythrocytes 20 healthy subjects (10 men, 10 women) aged 34 to 54 years (mean = 37.8 +/- 9.1) were studied. In patients with acute myocardial infarction and in control subjects serum potassium levels (Ks), erythrocyte potassium content (Ke) and urine potassium level (Ku) had been determined. Serum and erythrocyte potassium levels were assessed by Mayer method with the use of flame photometer. Urine potassium level was also determined by flame photometry. Values of serum and erythrocyte potassium level were given in mmol/l, and urine potassium levels in mmol/h. Ks, Ke and Ku values at 1 to 4 days were compared with one other and with levels in the control group and in healthy subjects as well as with values assumed as normal. At 1 day of the myocardial infarction Ks-3.87 +/- 0.58 mmol/l was significantly lower as compared with Ks at 2, 3 and 4 days and with values in the control group: Ks = 4.4 +/- 0.49 mmol/l and in healthy subjects: Ks = 4.2 +/- 0.36 mmol/l (p less than 0.0001). Ke levels at 1 and 2 days were 98.3 +/- 5.6; 99.2 +/- 5.3 mmol/l; significantly lower as compared with the levels at 4 days (Ke = 102.5 +/- 5.8 mmol/l p less than 0.05) and as compared with the levels in the control group: Ke = 104.5 +/- 6.1 mmol/l (p less than 0.05) and in healthy subjects: Ke-102.6 +/- 5.8 mmol/l (p less than 0.01). In contrast Ku level at 1 day of the infarction was 4.6 +/- 3.2 mmol/h and it was significantly higher as compared with excretion levels on the remaining days and in the control group: Ku = 2.7 +/- 0.7 mmol/h (p less than 0.0001). The present studies show changes in the potassium level in the acute phase of the myocardial infarction consisting in a decrease of Ks and Ke levels and an increase in Ku level, mainly at 1 day of the infarction.

In this paper the level of Na, K and Cl was determined on 108 kidney slices obtained from 12 kidney, removed from 6 clinical healthy piglets. The animals were 4 weeks old. The kidney tissue prepared by method as described by Appelboom et al. (1958). The electrolyte concentration in the cortex, outer medulla and inner medulla was calculated per 1 kg wet and dry tissue. There is a distinct (significant differences) electrolyte gradient in the piglet kidney tissue (the maximum electrolyte concentration in the papilla area). Low Na content even in inner medulla, indicates little capacity for urine concentration in the 4 week old piglets. Individual differences of the electrolyte content in kidney tissue, may indicate different rate of functional development of piglets kidney. No significant difference between left and right kidney was stated in the electrolytes concentration.

Lymphocytes of the fresh blood have a negative potential inside in relation to the extracellular medium. The value of the transmembrane potential depends on the concentration of potassium and chloride ions in the extracellular medium.

Two cases of hyperkalaemic periodic paralysis with myotonic symptoms were treated successfully with salbutamol. The methods of managing the hyperkalaemic form of periodic paralysis are discussed in brief.