No abstract

Magnesium, beyond any doubt, plays an important role in metabolism. Alterations of magnesium levels have an impact on many organs and systems, especially during aging. We had 156 participants aged 60–93 years (average 74.7 years) in our survey. Of them, 49 were men and 107 were women. Treatment with loop diuretics (Furosemid and Bumetanide) and magnesium levels was correlated, as well as the influence of magnesium levels on life span. Serum magnesium levels were measured in patients receiving diuretics and in the control group. Also, magnesium levels were measured in patients who passed away in the course of their disease and were compared with the control group. Magnesium levels in the diuretic group (100 patients) were 0.93 ± 0.094 mmol/l, while the average levels in the control group of 56 patients were 0.89 ± 0.075 mmol/l. In 29 patients who passed away, average magnesium levels were 0.92 ± 0.078 mmol/l, while in the control group (127 patients), magnesium levels were 0.93 ± 0.083 mmol/l. The differences were not statistically significant. There were no differences in serum magnesium of the elderly persons investigated regarding age group, gender, or type of diuretics. If methods of determining ionizing magnesium in serum or intracellular magnesium are not available, normal magnesium values in the serum are to be taken with a qualified acceptance.

The aim of our study was to investigate the effects of ifenprodil and MK-801 on D,L-homocysteine thiolactone induced seizures in adult rats.Male Wistar rats were divided into following groups: 1. Saline-treated (C, n=10); 2. D,L-homocysteine thiolactone 8 mmol/kg, i.p. (H, n=7); 3. Ifenprodil 20 mg/kg i.p. (IF, n=8); 4. MK-801 0.5 mg/kg, i.p. (MK, n=8) and 5. Groups that received IF or MK 30 minutes prior to H (IFH, n=8 and MKH, n=8). Seizure behavior was assessed by incidence, latency, number and intensity of seizure episodes. Seizure severity was described by a descriptive scale with grades 0-4. Lethality in experimental group was recorded 90 min and 24 h upon D,L-homocysteine thiolactone administration.There were no behavioral signs of seizure activity in groups C, IF and MK.Pre-treatment with MK-801 (MKH) showed tendency to reduced incidence of convulsions, latency to the first seizure onset and the severity of seizure episodes, but statistical significance was not attained comparing to the H group. However, median number of seizure episodes was significantly decreased in MKH (p<0.05), comparing to the H group. On the other hand, ifenprodil (IFH) decreased the latency to the first seizure onset and increased the median number of seizure episodes (p<0.05). The majority of seizure episodes in IFH (72.1%, p<0.05) and MKH (73.1%, p<0.05) groups was grade 2 and significantly different comparing to the H (36.0%). Our findings suggest that MK-801 has a mild anticonvulsive effect on D,L-homocysteine thiolactone induced seizures in adult rats.

Alcohol intake is associated with numerous degenerative disorders, and the detrimental effects of alcohol may be due to its influence on plasma membrane and cellular transport systems. The aim of the present study was to compare in vitro and in vivo effects of ethanol on rabbit erythrocyte ATPase activities and correlate them with ethanol-induced oxidative stress. Age-matched male rabbits were given 5% ethanol in 2% sucrose solution, for 6 weeks ad libitum; control animals were given tap water. Daily intake of ethanol was 5 g/kg body weight; this experimental regimen resulted in an average serum ethanol concentration of 16.77 +/- 2.00 mM/l. After this period, blood was collected, serum ethanol concentration was determined and erythrocyte membranes were prepared according to the method of Post et al. Activities of Na(+)/K(+)- and Mg(2+)-ATPases were determined. Thiobarbituric acid-reactive substance (TBARS) assay was used to detect levels of lipid peroxidation, a major indicator of oxidative stress. In vitro ethanol inhibits both Na(+)/K(+)-ATPase and Mg(2+)-ATPase, but Na(+)/K(+)-ATPase is more sensitive to the ethanol-induced inhibition. Increasing concentration of ethanol increased TBARS production, but significant difference was attained only at 5 and 12.5 mM of ethanol. Chronic ethanol consumption induced significant increase in Na(+)/K(+)- and Mg(2+)-ATPase activity, and TBARS production. Our results suggest that increased ATPase activity induced by chronic ethanol consumption is due to oxidative, induced modification of membrane phospholipids and proteins, which are responsible for inhibition of ATPase activity. Increased production of TBARS induced by in vitro exposure to ethanol is not the only factor that influences ATPases activity. Further research is needed to elucidate this relationship.

The concentration of catecholamines in the hypothalamus and reproductive organs of rats with hypothalamic lesions placed on the day of birth was investigated. In an attempt to contribute to the discussion concerning the role of catecholamines in regulation of puberty, the aim of this study was to examine the content of hypothalamic, ovarian and uterine catecholamines in female rats with precocious vaginal opening. The animals were sacrificed on the day of precocious puberty, which occurred at the age of 25.71 +/- 0.98 days. The data obtained were compared with intact (pubertal) controls obtained on the day of vaginal opening (40.13 +/- 1.35 days) as well as in infantile intact controls of corresponding age of the lesioned animals. In the ovaries of both animals (i.e. lesioned and sacrificed on day of vaginal opening and the infantile controls of corresponding age), small and medium sized follicles were present. Ruptured follicles were evident only in the pubertal controls. The mass of ovaries and uteri from lesioned rats was also significantly lower than in the pubertal controls. Concentrations of norepinephrine in both ovaries and uteri on the day of vaginal opening of the animals with posterior hypothalamic lesions and of infantile controls, was significantly higher than in pubertal controls on the day of vaginal opening. Epinephrine was significantly higher in the uterine tissues of lesioned and infantile controls as compared to pubertal animals. The levels of dopamine and norepinephrine in the hypothalamus of lesioned and pubertal controls on the day of vaginal opening were significantly higher than in infantile controls.(ABSTRACT TRUNCATED AT 250 WORDS)