[Selected markers of bone metabolism in boys with constitutional delay of growth and puberty]. / Wybrane wskazniki metabolizmu kostnego u chlopców z konstytucjonalnie wolnym przebiegiem wzrastania i rozwoju.

The aim of the study was to determine serum concentration and urinary excretion of selected parameters of bone metabolism in boys with constitutional delay of growth and puberty (CDGP) in the relation to pubertal stages. The study group consisted of 41 boys (aged 8 to 18 yrs) with CDGP. Patients were divided on the basis of Tanner's criteria into 4 groups according to the pubertal stage. Serum alkaline phosphatase (AP) activity and serum osteocalcin (OC) concentration as markers of bone growth, as well as urinary deoxypyridinoline (DPD) as a marker of bone resorption were determined. Serum AP activity in 31 (75.6%) boys was within normal age range. Mean values of serum AP activity increased insignificantly from I to IV stage of puberty. Serum OC concentrations were normal in 33 (80.5%) patients. Eight (19.5%) boys showed decreased values of serum OC concentration. Mean OC concentration insignificantly increased with the pubertal stages. DPD urinary excretion was within normal age range in all patients and was the highest in stage III of pubertal stage. No significant abnormalities of bone metabolism parameters in boys with constitutional delay of growth and puberty were found.

[Taurine as a regulator of fluid-electrolyte balance and arterial pressure]. / Tauryna jako regulator równowagi wodno-elektrolitowej i cisnienia tetniczego krwi.

Taurine is a sulfonic beta-amino acid which occurs in the highest concentration in the brain, the retina and in the myocardium. In cardiomyocytes it presents about 50% of free amino acids and plays a role as an osmoregulator, an inotropic factor and has an antiarrhythmic property. Moreover, taurine lowers arterial pressure by extension of diuresis and by vasodilatation. Similar effect on the vascular system and arterial pressure is exerted by atrial natriuretic peptide (ANP). Increase of both ANP secretion and myocardial taurine concentration is present in the same diseases as congestive cardiac failure, hypertension and hypernatremia. The aim of the study was the evaluation of general taurine depletion, caused by making the rats drink guanidinoethyl sulfonate (GES)--an inhibitor of taurine transport affecting fluid balance and arterial pressure as well as plasma ANP concentration under normal conditions and after increase of sodium load. The 103 male Wistar rats weighing 250-300 g were used. The animals were separated into 5 groups. Control group received tap water to drink. Group II was sodium-loaded by drinking 171 mmol/l NaCl. In group III depletion of taurine was obtained by the intake of 60 mmol/l GES. Rats in group IV were drinking 60 mmol/l GES in 171 mmol/l NaCl. Group V was made to drink 200 mmol/l taurine in 171 mmol/l NaCl. All animals had standard food and were able at any time to drink. Duration of the experiment was 20 days. At the onset and after 10 and 20 days the rats were weighed and their systolic blood pressure was measured by tail plethysmography. After 10 and 20 days of the study, plasma and myocardium taurine concentration, ANP, hematocrit, plasma osmolity, natremia, kalemia, urea and creatinine concentrations were determined. Taking GES for 20 days led to 43% decrease of plasma taurine and its myocardium content about 50% as compared to control group (Tab. 2). High, statistically significant correlation (r = 0.50, p < 0.001) between myocardium taurine and plasma ANP was found. The animals with taurine depletion had significantly lower (about 30%) plasma ANP concentration (Tab. 3), higher natremia (Tab. 4) and their arterial pressure increased due to sodium load. Systolic pressure was 11 mm Hg higher in that group in comparison to control and other groups (Tab. 1). However, the sodium-loading of the rats that drank taurine solution led to an increase of hematocrit, plasma osmolity, urea concentration and body mass gain as compared to control group, but without any arterial pressure increase. The sodium-loaded rats with normal plasma and myocardium taurine concentration were affected in a similar manner. The rats with higher myocardium taurine concentration had lower heart mass index. Results of this work lead to the following conclusions: 1. Depletion of taurine in hearts of examined rats leads to a decrease of plasma atrial natriuretic peptide (ANP) concentration in plasma. 2. ANP secretion caused by salt loading is lower in animals with taurine depletion than in normal animals. 3. Sodium-loading of animals with taurine depletion leads to hypernatremia and to an increase of arterial pressure. 4. Addition of taurine to animals loaded with sodium may lead to their dehydration.

[Superoxide dismutase activity of erythrocytes and their osmotic fragility]. / Aktywnosc dysmutazy ponadtlenkowej erytrocytów a ich opornosc osmotyczna.

Blood samples were obtained from 15 diabetic patients (type I) and 10 healthy subjects. Erythrocyte superoxide dismutase activity, Heinz bodies and osmotic fragility were determined. Our results suggest that decreased activity of erythrocyte SOD predisposes to denaturation of haemoglobin (Heinz bodies) and haemolysis (increased osmotic fragility).